WO2003026638A1

WO2003026638A1 - Neuroprotective treatment methods using selective inos inhibitors

Info

Publication number: WO2003026638A1
Application number: PCT/US2002/030214
Authority: WO
Inventors: Pamela T. Manning; Jane R. Connor
Original assignee: Pharmacia Corporation
Priority date: 2001-09-24
Filing date: 2002-09-24
Publication date: 2003-04-03
Also published as: CA2455989A1; MXPA04002710A; JP2005508910A; US20030119826A1; ZA200402288B; PL371774A1; BR0212989A; IL161005A0; KR20040039394A; EP1429752A1; CN1556698A; AU2002327042A2

Abstract

Therapeutic methods for the prevention and treatment of neurodegenerative conditions are described, the methods including administering to a subject in need thereof a neuroprotective effective amount of a selective inhibitor of inducible nitric oxide synthase.

Description

NETJROPROTECTIVE TREATMENT METHODS USING SELECTIVE iNOS INHIBITORS

BACKGROUND OF THE INVENTION

The present invention relates in general to methods of medical treatment using selective inhibitors of the inducible form of nitric oxide synthase (iNOS), and more particularly to novel methods useful for providing neuroprotection to aid in the medical prevention and treatment of neurodegenerative conditions and diseases.

Neuroprotection refers to the protection of healthy but at-risk neurons that are located in the vicinity of dead or dying cells after the end or removal of a primary insult. Primary destructive events in the CNS include, for example, physical trauma such as compression or crush injury, and hypoxia due to ischemia brought about by an event such as a stroke. These primary destructive events may be the result of any number of CNS conditions, including retinal conditions such as glaucoma and retinopathy of varied etiology, as well as diseases and conditions of the brain such as stroke, Alzheimer's disease, and amyotrophic lateral sclerosis (ALS). A goal of neurologists, neurosurgeons and more recently, opthalmologists has therefore been to apply the principle of neuroprotection in the treatment of such diseases and conditions, to enhance the survival of remaining neurons to maintain physiologic function. An important characteristic of neuroprotective strategy is that it affords treatment of a variety of CNS disorders for which the specific etiology is either unknown or differs from patient to patient.

Nitric oxide (NO) is a free radical gas and in the nervous system acts as a neurotransmitter. In the CNS, NO can be neurodestructive and neuroprotective. Further complicating an understanding of the role of NO in CNS neurodegeneration is the finding that NO is produced by any one of several isoforms ofthe enzyme nitric oxide synthase. The activity of NO was initially as discovered in the early 1980's when it was found that vascular relaxation caused by acetylcholine is dependent on the presence of the vascular endothelium. The factor derived from the endothelium, called endothelium-derived relaxing factor (EDRF), that mediates such vascular relaxation is now known to be NO that is generated in the vascular endothelium by one isoform of NOS. The activity of NO as a vasodilator has been known for well over 100 years. In addition, NO is the active species derived from known nitrovasodilators including amylnitrite, and glyceryltrinitrate. Nitric oxide is also an endogenous stimulator of soluble guanylate cyclase and thus stimulates cyclic guanosime monophosphate (cGMP) production. When NOS is inhibited by N-monomethylarginine (L- NMMA), cGMP formation is completely prevented. In addition to endothelium-dependent relaxation, NO is known to be involved in a number of biological actions including cytotoxicity of phagocytic cells and cell-to-cell communication in the central nervous system. The identification of EDRF as NO coincided with the discovery of a biochemical pathway by which NO is synthesized from the amino acid L-arginine by the enzyme NO synthase. There are at least three types of NO synthase as follows:

(i) a constitutive, Ca++/calmodulin dependent enzyme, located in the endothelium, that releases NO in response to receptor or physical stimulation.

(ii) a constitutive, Ca++/calmodulin dependent enzyme, located in the brain, that releases NO in response to receptor or physical stimulation.

(iii) a Ca++ independent enzyme, a 130 kD protein, which is induced after activation of vascular smooth muscle, macrophages, endothelial cells, and a number of other cells by endotoxin and cytokines. Once expressed this inducible nitric oxide synthase (hereinafter "iNOS") generates NO continuously for long periods.

Thus, nitric oxide produced by the family of nitric oxide synthase enzymes possesses a wide range of physiological and pathophysiological actions (Moncada et al, Pharmacol. Rev. 43: 109-142, 1991. The NO released by each ofthe two constitutive enzymes acts as a transduction mechanism underlying several physiological responses. In contrast, the NO produced by the inducible enzyme is a cytotoxic molecule for tumor cells and invading microorganisms. Inducible NOS is also associated with the inflammation of osteoarthritis. h the CNS, the inducible form of NOS appears to be related to the neurodegeneration that characterizes several human disorders. More specifically, iNOS is not normally expressed in the brain but can be induced in astrocytes and microglia following insult such as viral infection or trauma. For example, cerebral ischemia induces iNOS activity in the brain. Ischemia-induced cerebral infarcts in iNOS knockout mice are much smaller in volume than the infarcts in wild-type controls (Shareef et al, Invest. Ophthalmol. Vis. Sci. 40:2884-91, 1999). Inducible NOS is implicated in the neurodegeneration associated with CNS diseases and conditions such as stroke, multiple sclerosis, amyotropic lateral sclerosis, Alzheimer's disease, and acquired immune deficiency syndrome (Shareef et al).

In addition, the distribution of NOS isoforms in noraial and glaucomatous optic nerve heads implicate iNOS in the neurodegeneration of glaucoma (Shareef et al). Normals appear to express both constitutive forms of NOS (Type (i) and Type (ii)). Type (i) is present in many astrocytes throughout the optic nerve, and in its vascular system, and likely plays a role in intercellular signaling and regulation of vasodilation and blood flow. Type (ii) is localized to the vascular endothelium throughout the optic nerve head vasculature and may have a neuroprotective role in addition to helping regulate blood flow. In contrast, iNOS is not normally expressed in the optic nerve head, but appears in the optic nerve of rats with experimentally-induced, chronic moderately elevated intraocular pressure (IOP) (Shareef et al.). In rats with chronic moderately elevated IOP, aminoguanidine, an inhibitor of iNOS, blocks loss of retinal ganglion cells (Neufeld et al., Proc. Natl. Acad. Sci. USA 96:9944-48, 1999). In addition, uveitis, which is characterized by inflammation, may involve increased iNOS activity stimulated by the eytokine tumor necrosis factor-α (TNF-α). Thus, No produced by iNOS may play a role in neurodegenerative conditions ofthe CNS having varied etiology.

The following individual publications disclose compounds that inhibit nitric oxide synthesis and preferentially inhibit the inducible isoform of nitric oxide synthase: PCT Patent Application No. WO 96/35677. PCT Patent Application No. WO 96/33175. PCT Patent Application No. WO 96/15120. PCT Patent Application No. WO 95/11014. PCT Patent Application No. WO 95/11231. PCT Patent Application No. WO 99/46240. PCT Patent Application No. WO 95/24382. PCT Patent Application No. WO 94/12165. PCT Patent Application No. WO 94/14780. PCT Patent Application No. WO 93/13055.

PCT Patent Application No. WO 99/62875.

European Patent No. EP0446699A1.

U.S. Patent No. 5,132,453.

U.S. Patent No. 5,684,008.

U.S. Patent No. 5,830,917.

U.S. Patent No. 5,854,251.

U.S. Patent No. 5,863,931.

U.S. Patent No. 5,919,787.

U.S. Patent No. 5,945,408.

U.S. Patent No. 5,981,511.

PCT Patent Application No. WO 95/25717 discloses certain amidino derivatives as being useful in inhibiting inducible nitric oxide synthase.

PCT Patent Application No. WO 99/62875 discloses further amidino compounds as being useful in inhibiting inducible nitric oxide synthase.

Against this background, increasing interest has developed in finding novel neuroprotective agents and methods for the treatment and prevention of various neurodegenerative conditions relating to an excess of iNOS activity, and further for improved overall treatment efficacy with minimal toxicity and adverse side effects. While basic findings regarding the biochemistry and functions of iNOS implicate it in various conditions including neurodegenerative conditions among many others, known neuroprotective methods to treat and prevent these conditions do not currently include methods of therapy using iNOS- selective inhibitors. It would therefore be advantageous to find and describe new methods of neuroprotective therapy using iNOS-selective inhibitors for treating neurodegenerative conditions that involve an excess of iNOS activity.

SUMMARY OF THE INVENTION

The present invention is directed toward a method for preventing or treating a neurodegenerative condition in a subject in need of such treatment or prevention, the method comprising administering to the subject a neuroprotective effective amount of an inducible nitric oxide synthase selective inhibitor or pharmaceutically acceptable salt thereof or prodrug thereof, wherein the inducible nitric oxide synthase inhibitor is selected from the group consisting of: a compound having Formula I

I

or a pharmaceutically acceptable salt thereof, wherein:

R¹ is selected from the group consisting of H, halo and alkyl which may be optionally substituted by one or more halo;

R² is selected from the group consisting of H, halo and alkyl which may be optionally substituted by one or more halo; with the proviso that at least one of R¹ or R² contains a halo;

R⁷ is selected from the group consisting of H and hydroxy;

J is selected from the group consisting of hydroxy, alkoxy, and NR³R wherein;

R is selected from the group consisting of H, lower alkyl, lower alkylenyl and lower alkynyl;

R is selected from the group consisting of H, and a heterocyclic ring in which at least one member ofthe ring is carbon and in which 1 to about 4 heteroatoms are independently selected from oxygen, nitrogen and sulfur and said heterocyclic ring may be optionally substituted with heteroarylamino, N-aryl-N-alkylamino, N-heteroarylamino-N-alkylamino, haloalkylthio, alkanoyloxy, alkoxy, heteroaralkoxy, cycloalkoxy, cycloalkenyloxy, hydroxy, amino, thio, nitro, lower alkylamino, alkylthio, alkylthioalkyl, arylamino, aralkylamino, arylthio, alkylsulfinyl, alkylsulfonyl, alkylsulfonamido, alkylaminosulfonyl, amidosulfonyl, monoalkyl amidosulfonyl, dialkyl amidosulfonyl, monoarylamidosulfonyl, arylsulfonamido, diarylamidosulfonyl, monoalkyl monoaryl amidosulfonyl, arylsulfmyl, arylsulfonyl, heteroarylthio, heteroarylsulfinyl, heteroarylsulfonyl, alkanoyl, alkenoyl, aroyl, heteroaroyl, aralkanoyl, heteroaralkanoyl, haloalkanoyl, alkyl, alkenyl, alkynyl, alkylenedioxy, haloalkylenedioxy, cycloalkyl, cycloalkenyl, lower cycloalkylalkyl, lower cycloalkenylalkyl, halo, haloalkyl, haloalkoxy, hydroxyhaloalkyl, hydroxyaralkyl, hydroxyalkyl, hydoxyheteroaralkyl, haloalkoxyalkyl, aryl, aralkyl, aryloxy, aralkoxy, aryloxyalkyl, saturated heterocyclyl, partially saturated heterocyclyl, heteroaryl, heteroaryloxy, heteroaryloxyalkyl, arylalkyl, heteroarylalkyl, arylalkenyl, heteroarylalkenyl, cyanoalkyl, dicyanoalkyl, carboxamidoalkyl, dicarboxamidoalkyl, cyanocarboalkoxyalkyl, carboalkoxyalkyl, dicarboalkoxyalkyl, cyanocycloalkyl, dicyanocycloalkyl, carboxamidocycloalkyl, dicarboxamidocycloalkyl, carboalkoxycyanocycloalkyl, carboalkoxycycloalkyl, dicarboalkoxycycloalkyl, formylalkyl, acylalkyl, dialkoxyphosphonoalkyl, diaralkoxyphosphonoalkyl, phosphonoalkyl, dialkoxyphosphonoalkoxy, diaralkoxyphosphonoalkoxy, phosphonoalkoxy, dialkoxyphosphonoalkylamino, diaralkoxyphosphonoalkylamino, phosphonoalkylamino, dialkoxyphosphonoalkyl, diaralkoxyphosphonoalkyl, guanidino, amidino, and acylamino;

a compound having a structure corresponding to Formula II

or a pharmaceutically acceptable salt thereof, wherein X is selected from the group consisting of -S-, -S(O)-, and -S(O)2-. Preferably, X is -S-. R¹²is selected from the group consisting of Ci-Cβ alkyl, C2-Cg alkenyl, C2-C6 alkynyl, C1-C5 alkoxy-Ci alkyl, and C1-C5 alkylthio-Ci alkyl wherein each of these groups is optionally substituted by one or more

19 substituent selected from the group consisting of -OH, alkoxy, and halogen. Preferably, R is Ci-Cg alkyl optionally substituted with a substituent selected from the group consisting of

-OH, alkoxy, and halogen. With respect to R¹³ and R¹⁸, R¹⁸ is selected from the group consisting of -OR²⁴ and -N(R²⁵)(R²⁶), and R¹³ is selected from the group consisting of -H, - OH, -C(O)-R²⁷, -C(O)-O-R²⁸, and -C(O)-S-R²⁹; or R¹⁸ is -N(R³⁰)-, and R¹³ is -C(O)-, wherein R¹⁸ and R¹³ together with the atoms to which they are attached form a ring; or R¹⁸ is -O-, and R¹³ is -C(R³¹)(R³²)-, wherein R^1S and R¹³ together with the atoms to which they are attached form a ring. If R¹³ is -C(R3²¹)(R³²)-, then R¹⁴ is -C(O)-O-R³³; otherwise R¹⁴ is -H. R¹¹, R¹⁵,

R¹⁶, and R¹⁷ independently are selected from the group consisting of -H, halogen, Ci-Cg alkyl, C2-Cg alkenyl, C2-Cg alkynyl, and C1-C5 alkoxy-Ci alkyl. R¹⁹ and R²⁰ independently are selected from the group consisting of -H, Ci-Cβ alkyl, C2-C5 alkenyl, C2-C6 alkynyl, and

C1-C5 alkoxy-Ci alkyl. With respect to R²¹ and R²², R²¹ is selected from the group consisting of -H, -OH, -C(O)-O-R³⁴, and -C(O)-S-R³⁵, and R²² is selected from the group consisting of -H, -OH, -C(O)-O-R³⁶, and -C(O)-S-R³⁷; orR²¹ is -O-, andR²² is -C(O)-,

91 99 91 wherein R and R together with the atoms to which they are attached foπn a ring; or R is

99 1 T?

-C(O)-, and R is -O-, wherein R and R together with the atoms to which they are attached form a ring. R²³ is C alkyl. R²⁴ is selected from the group consisting of -H and C\-

Cg alkyl, wherein when R²⁴ is Ci-Cβ alkyl, R²⁴ is optionally substituted by one or more moieties selected from the group consisting of cycloalkyl, heterocyclyl, aryl, and heteroaryl. With respect to R²⁵ and R²⁶, R²⁵ is selected from the group consisting of -H, alkyl, and alkoxy, and R²⁶ is selected from the group consisting of -H, -OH, alkyl, alkoxy, -C(O)-R³⁸, -C(O)-O-R³⁹, and -C(O)-S-R⁴⁰; wherein when R²⁵ and R²⁶ independently are alkyl or alkoxy, R²⁵ and R² independently are optionally substituted with one or more moieties selected from the group consisting of cycloalkyl, heterocyclyl, aryl, and heteroaryl; or R²⁵ is -H; and R²⁶ is selected from the group consisting of cycloalkyl, heterocyclyl, aryl, and heteroaryl. R²⁷, R²⁸, R²⁹, R³⁰, R³¹, R³², R³³, R³⁴, R³⁵, R³⁶, R³⁷, R³⁸, R³⁹, and R⁴⁰ independently are selected from the group consisting of -H and alkyl, wherein alkyl is optionally substituted by one or more moieties selected from the group consisting of cycloalkyl, heterocyclyl, aryl, and heteroaryl. When any of R¹¹, R¹², R¹³, R¹⁴, R¹⁵, R¹⁶, R¹⁷, R¹⁸, R19⁹, R²⁰, R²¹, R²², R²³, R²⁴, R²⁵, R²⁶, R²⁷, R²⁸, R²⁹, R³⁰, R³¹, R³², R³³, R³⁴, R³⁵ R³⁶, R³⁷, R³⁸, R³⁹, and R⁴⁰ independently is a moiety selected from the group consisting of alkyl, alkenyl, alkynyl, alkoxy, alkylthio, cycloalkyl, heterocyclyl, aryl, and heteroaryl, then the moiety is optionally substituted by one or more substituent selected from the group consisting of -OH, alkoxy, and halogen; a compound is represented by Formula III

or a pharmaceutically acceptable salt thereof, wherein: R⁴¹ is H or methyl; and R⁴² is H or methyl; a compound of formula IV

IV or a pharmaceutically acceptable salt thereof; a compound of Formula V:

or a pharmaceutically acceptable salt thereof, wherein:

R⁴³ is selected from the group consisting of hydrogen, halo, C_\-Cs alkyl and C1-C5 alkyl substituted by alkoxy or one or more halo;

R⁴⁴ is selected from the group consisting of hydrogen, halo, -C5 alkyl and C1-C5 alkyl substituted by alkoxy or one or more halo;

R⁴⁵ is C₁-C₅ alkyl or Cι-C₅ alkyl be substituted by alkoxy or one or more halo; a compound of Formula VI:

VI or a pharmaceutically acceptable salt thereof, wherein:

R⁴⁶ is CrC₅ alkyl, said C₁-C₅ alkyl optionally substituted by halo or alkoxy, said alkoxy optionally substituted by one or more halo; A compound of Formula VII

VII or a pharmaceutically acceptable salt thereof, wherein:

R⁴⁷ is selected from the group consisting of hydrogen, halo, C C₅ alkyl and -Cs alkyl substituted by alkoxy or one or more halo;

R is selected from the group consisting of hydrogen, halo, C_\-Cs alkyl and Ci-C₅ alkyl substituted by alkoxy or one or more halo;

R⁴⁹ is C H₁ι_.--CC₅ aallkkyyll oorr CC₁₁--CC₅₅ aallkkyyll bbee ssiubstituted by alkoxy or one or more halo; a compound of Formula VIII

VIII or a pharmaceutically acceptable salt thereof, wherein:

R⁵⁰ is -C₅ alkyl, said C1-C₅ alkyl optionally substituted by halo or alkoxy, said alkoxy optionally substituted by one or more halo; a compound of formula IX

IX or a pharmaceutically acceptable salt thereof, wherein:

R⁵⁰ is selected from the group consisting of hydrogen, halo, and C^Cs alkyl, said -

C₅ alkyl optionally substituted by halo or alkoxy, said alkoxy optionally substituted by one or more halo;

R⁵¹ is selected from the group consisting of hydrogen, halo, and C C₅ alkyl, said Q-

R⁵² is -C₅ alkyl, said d-Cs alkyl optionally substituted by halo or alkoxy, said alkoxy optionally substituted by one or more halo;

R⁵³ is selected from the group consisting of hydrogen, halo, and -Cs alkyl, said Ci-

C₅ alkyl optionally substituted by halo or alkoxy, said alkoxy optionally substituted by one or more halo; and

R⁵⁴ is selected from the group consisting of halo and Cι-C₅ alkyl, said -C₅ alkyl optionally substituted by halo or alkoxy, said alkoxy optionally substituted by one or more halo; and a compound of formula X

X or a pharmaceutically acceptable salt thereof, wherein:

R⁵⁵ is -Cs alkyl, said -C₅ alkyl optionally substituted by halo or alkoxy, said alkoxy optionally substituted by one or more halo.

The neurodegenerative condition is, for example, stroke, multiple sclerosis, amyotrophic lateral sclerosis, Alzheimer's disease, epilepsy, dementia of acquired immune deficiency syndrome, cerebral ischemia including focal cerebral ischemia, or physical trauma such as crush or compression injury in the CNS.

The methods described above are thus useful in the treatment and prevention of neurodegenerative conditions including the neurodegeneration of stroke, multiple sclerosis, amyotrophic lateral sclerosis, Alzheimer's disease, epilepsy, dementia of acquired immune deficiency syndrome, cerebral ischemia including focal cerebral ischemia, and phyiscal trauma such as crush or compression injury.

DETAILED DESCRIPTION OF INVENTION

The following detailed description is provided to aid those skilled in the art to practice the present invention. However, this detailed description should not be construed to unduly limit the present invention, inasmuch as modifications and variations in the exemplary embodiments discussed herein can be niade by those of ordinary skill in the art without departing from the scope ofthe appended claims.

The contents of each of the primary references cited herein, including the contents of the references cited within the primary references, are herein incorporated by reference in their entirety.

The present invention encompasses therapeutic methods using novel selective iNOS inhibitors to treat or prevent neurodegenerative conditions, including therapeutic methods of use in medicine for preventing and treating neurodegeneration of stroke, multiple sclerosis, amyotrophic lateral sclerosis, Alzheimer's disease, epilepsy, dementia of acquired immune deficiency syndrome, cerebral ischemia including focal cerebral ischemia, and phyiscal trauma such as crush or compression injury in the CNS, including a crush or compression injury ofthe brain, spinal cord, nerves or retina. The therapeutic methods include administering to a subject in need thereof a neuroprotective effective amount of a selective inhibitor of inducible nitric oxide synthase having a formula selected from Formulas I-X. .

a. Definitions

The following definitions are provided in order to aid an understanding ofthe detailed description ofthe present invention:

The term "alkyl", alone or in combination, means an acyclic alkyl radical, linear or branched, preferably containing from 1 to about 10 carbon atoms and more preferably containing from 1 to about 6 carbon atoms. "Alkyl" also encompasses cyclic alkyl radicals containing from 3 to about 7 carbon atoms, preferably from 3 to 5 carbon atoms. Said alkyl radicals can be optionally substituted with groups as defined below. Examples of such radicals include methyl, ethyl, chloroethyl, hydroxyethyl, n-propyl, isopropyl, n-butyl, cyanobutyl, isobutyl, sec-butyl, tert-butyl, pentyl, aminopentyl, iso-amyl, hexyl, octyl and the like.

The term "alkenyl" refers to an unsaturated, acyclic hydrocarbon radical, linear or branched, in so much as it contains at least one double bond. Such radicals containing from 2 to about 6 carbon atoms, preferably from 2 to about 4 carbon atoms, more preferably from 2 to about 3 carbon atoms. Said alkenyl radicals may be optionally substituted with groups as defined below. Examples of suitable alkenyl radicals include propenyl, 2-chloropropylenyl, buten-1-yl, isobutenyl, penten-1-yl, 2-methylbuten-l-yl, 3-methylbuten-l-yl, hexen-1-yl, 3- hydroxyhexen-1-yl, hepten-1-yl, and octen-1-yl, and the like.

The term "alkynyl" refers to an unsaturated, acyclic hydrocarbon radical, linear or branched, in so much as it contains one or more triple bonds, such radicals containing 2 to about 6 carbon atoms, preferably from 2 to about 4 carbon atoms, more preferably from 2 to about 3 carbon atoms. Said alkynyl radicals may be optionally substituted with groups as defined below. Examples of suitable alkynyl radicals include ethynyl, propynyl, hydroxypropynyl, butyn-1-yl, butyn-2-yl, pentyn-1-yl, pentyn-2-yl, 4-methoxypentyn-2-yl, 3- methylbutyn-1-yl, hexyn-1-yl, hexyn-2-yl, hexyn-3-yl, 3,3-dimethylbutyn-l-yl radicals and the like. The term "alkoxy" embrace linear or branched oxy-containing radicals each having alkyl portions of 1 to about 6 carbon atoms, preferably 1 to about 3 carbon atoms, such as a methoxy radical. The term "alkoxyalkyl" also embraces alkyl radicals having one or more alkoxy radicals attached to the alkyl radical, that is, to form monoalkoxyalkyl and dialkoxyalkyl radicals. Examples of such radicals include methoxy, ethoxy, propoxy, butoxy and tert-butoxy alkyls. The "alkoxy" radicals may be further substituted with one or more halo atoms, such as fluoro, chloro or bromo, to provide "haloalkoxy" radicals. Examples of such radicals include fluoromethoxy, chloromethoxy, trifluoromethoxy, difluoromethoxy, trifluoroethoxy, fluoroethoxy, tetrafluoroethoxy, pentafluoroethoxy, and fluoropropoxy.

The term "alkylthio" embraces radicals containing a linear or branched alkyl radical, of 1 to about 6 carbon atoms, attached to a divalent sulfur atom. An example of "lower alkylthio" is methylthio (CH3-S-).

The term "alkylthioalkyl" embraces alkylthio radicals, attached to an alkyl group. Examples of such radicals include methylthiomethyl.

The term "halo" means halogens such as fluorine, chlorine, bromine or iodine atoms.

The term "heterocyclyl" means a saturated or unsaturated mono- or multi-ring carbocycle wherein one or more carbon atoms is replaced by N, S, P, or O. This includes, for example, the following structures:

wherein Z, Z¹, Z² or Z³ is C, S, P, O, or N, with the proviso that one of Z, Z¹, Z² or Z³ is other than carbon, but is not O or S when attached to another Z atom by a double bond or when attached to another O or S atom. Furthermore, the optional substituents are understood to be attached to Z, 7A, Z² or 7? only when each is C. The term "heterocyclyl" also includes fully saturated ring structures such as piperazinyl, dioxanyl, tetrahydrofuranyl, oxiranyl, aziridinyl, morpholinyl, pyrrolidinyl, piperidinyl, thiazolidinyl, and others. The term "heterocyclyl" also includes partially unsaturated ring structures such as dihydrofuranyl, pyrazolinyl, imidazolinyl, pyrrolinyl, chromanyl, dihydrothiophenyl, and others.

The term "heteroaryl" means a fully unsaturated heterocycle.

In either "heterocycle" or "heteroaryl," the point of attachment to the molecule of interest can be at the heteroatom or elsewhere within the ring.

The term "cycloalkyl" means a mono- or multi-ringed carbocycle wherein each ring contains three to about seven carbon atoms, preferably three to about five carbon atoms. Examples include radicals such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloalkenyl, and cycloheptyl. The term "cycloalkyl" additionally encompasses spiro systems wherein the cycloalkyl ring has a carbon ring atom in common with the seven- membered heterocyclic ring ofthe benzothiepine.

The tenn "oxo" means a doubly bonded oxygen.

The term "alkoxy" means a radical comprising an alkyl radical that is bonded to an oxygen atom, such as a methoxy radical. More prefened alkoxy radicals are "lower alkoxy" radicals having one to about ten carbon atoms. Still more preferred alkoxy radicals have one to about six carbon atoms. Examples of such radicals include methoxy, ethoxy, propoxy, isopropoxy, butoxy and tert-butoxy.

The term "aryl" means a fully unsaturated mono- or multi-ring carbocycle, including, but not limited to, substituted or unsubstituted phenyl, naphthyl, or anthracenyl.

The phrase "optionally substituted" means that the indicated radical may, but need not be substituted for hydrogen. Thus, the phrase "optionally substituted by one or more" means that if a substitution is made at the indicated moiety, more than one substitution is contemplated as well. In this regard, if more than one optional substituent exists, either substituent may be selected, or a combination of substituents may be selected, or more than one ofthe same substituent may be selected. By way of example, and not limitation, the phrase " -Cs alkyl optionally substituted by one or more halo or alkoxy" should be taken to mean, for example, that methyl, ethyl, propyl, butyl, or pentyl may have at all substitutable positions: hydrogen, fluorine, chlorine or other halogen, methoxy, ethoxy, propoxy, iso butoxy, tert-butoxy, pentoxy or other alkoxy radicals, and combinations thereof. Non- limiting examples include: propyl, wo-propyl, methoxypropyl, fluoromethyl, fluoropropyl, 1-fluoro-methoxymethyl and the like.

When a compound is described by both a structure and a name, the name is intended to correspond to the indicated structure, and similarly the structure is intended to correspond with the indicated name.

The term "subject" as used herein refers to an animal, in one embodiment a mammal, and in an exemplary embodiment particularly a human being, who is the object of treatment, observation or experiment.

The terms "dosing" and "treatment" as used herein refer to any process, action, application, therapy or the like, wherein a subject, particularly a human being, is rendered medical aid with the object of improving the subject's condition, either directly or indirectly.

The term "therapeutic compound" as used herein refers to a compound useful in the prophylaxis or treatment of a neurodegenerative condition.

The term "combination therapy" means the administration of two or more therapeutic compounds to treat a therapeutic condition or disorder described in the present disclosure, for example glaucoma, retinitis, retinopathies, uveitis and ophthalmologic disorders characterized at least in part by retinal neurodegeneration. Such administration encompasses co-administration of these therapeutic agents in a substantially simultaneous manner, such as in a single capsule having a fixed ratio of active ingredients or in multiple, separate capsules for each active ingredient, h addition, such administration also encompasses use of each type of therapeutic agent in a sequential manner. In either case, the treatment regimen will provide beneficial effects ofthe drug combination in treating the conditions or disorders described herein.

The term "therapeutic combination" as used herein refers to the combination of the two or more therapeutic compounds and to any pharmaceutically acceptable carriers used to provide dosage forms that produce a beneficial effect of each therapeutic compound in the subject at the desired time, whether the therapeutic compounds are administered substantially simultaneously, or sequentially.

The term "therapeutically effective" as used herein refers to a characteristic of an amount of a therapeutic compound, or a characteristic of amounts of combined therapeutic compounds in combination therapy. The amount or combined amounts achieve the goal of preventing, avoiding, reducing or eliminating the ophthalmologic condition.

The terms "inducible nitric oxide synthase" and "iNOS" as used interchangeably herein refer to the Ca⁺² -independent, inducible isoform ofthe enzyme nitric oxide synthase.

The terms "inducible nitric oxide synthase selective inhibitor", "selective iNOS inhibitor" and "iNOS selective inhibitor" as used interchangeably herein refer to a therapeutic compound that selectively inhibits the Ca⁺² -independent, inducible isoform of the enzyme nitric oxide synthase. A selective iNOS inhibitor is defined as producing the selective inhibition of iNOS compared to either endothelial NOS or neuronal NOS such that in vivo administration results in efficacy (ED₅₀ less than 100 mg/kg, but preferably less than 10 mg/kg in a rodent endotoxin model) and selectivity of at least 20-fold, but preferably 100- fold or greater with respect to eNOS as measured by elevation in mean arterial blood pressure and selectivity of at least 20-fold, but preferably 100-fold or greater with respect to nNOS as measured by reductions in gastrointestinal transit or penile erection.

The term "prodrug" refers to a compound that is a drug precursor which, following administration to a subject and subsequent absorption, is converted to an active species in vivo via some process, such as a metabolic process. Other products from the conversion process are easily disposed of by the body. The more preferred prodrugs are those involving a conversion process that produces products that are generally accepted as safe.

The term "neurodegeneration" refers to the process of cell destruction resulting from primary destructive events, and also secondary, delayed and progressive destructive mechanisms that are invoked by cells due to the ocunence ofthe primary destructive event. Primary destructive events include disease processes or physical injury or insult, including stroke, multiple sclerosis, amyotrophic lateral sclerosis, Alzheimer's disease, epilepsy, dementia of acquired immune deficiency syndrome, cerebral ischemia including focal cerebral ischemia, and physical trauma such as crush or compression injury in the CNS, including a crush or compression injury ofthe brain, spinal cord, nerves or retina, or any acute injury or insult producing neurodegeneration involving elevated levels of NO. Secondary destructive mechanisms include any mechanism that leads to the generation and release of neurotoxic molecules including NO, including apoptosis, depletion of cellular energy stores because of changes in mitochondrial membrane permeability, release or failure to reuptake excessive glutamte, reperfusion injury, and activity of cytokines and inflammation.

The term "neurodegenerative condition" refers to a primary destructive event or secondary destructive mechanism resulting in neurodegeneration.

The term "neuroprotection" refers to a therapeutic strategy for slowing or preventing the irreversible loss of neurons due to neurodegeneration after a primary destructive event, whether the neurodegenration loss is due to disease mechanisms associated with the the primary destructive event or due to secondary destructive mechanisms.

The term "neuroprotective effective" as used herein refers to a characteristic of an amount of a therapeutic compound, or a characteristic of amounts of combined therapeutic compounds in combination therapy. The amount or combined amounts achieve the goal of preventing, avoiding, reducing or eliminating neurodegeneration.

In one illustrative example of a selective iNOS inhibitor, treatment is facilitated through compounds having Formula I:

I or a pharmaceutically acceptable salt thereof, wherein:

R⁷ is selected from the group consisting of H and hydroxy; and

J is selected from the group consisting of hydroxy, alkoxy, and NR³R⁴ wherein; R³ is selected from the group consisting of H, lower alkyl, lower alkylenyl and lower alkynyl; and

R⁴ is selected from the group consisting of H, and a heterocyclic ring in which at least one member ofthe ring is carbon and in which 1 to about 4 heteroatoms are independently selected from oxygen, nitrogen and sulfur and said heterocyclic ring may be optionally substituted with heteroarylamino, N-aryl-N-alkylamino, N-heteroarylamino-N-alkylamino, haloalkylthio, alkanoyloxy, alkoxy, heteroaralkoxy, cycloalkoxy, cycloalkenyloxy, hydroxy, amino, thio, nitro, lower alkylamino, alkylthio, alkylthioalkyl, arylamino, aralkylamino, arylthio, alkylsulfinyl, alkylsulfonyl, alkylsulfonamido, alkylaminosulfonyl, amidosulfonyl, monoalkyl amidosulfonyl, dialkyl amidosulfonyl, monoarylamidosulfonyl, arylsulfonamido, diarylamidosulfonyl, monoalkyl monoaryl amidosulfonyl, arylsulfinyl, arylsulfonyl, heteroarylthio, heteroarylsulfinyl, heteroarylsulfonyl, alkanoyl, alkenoyl, aroyl, heteroaroyl, aralkanoyl, heteroaralkanoyl, haloalkanoyl, alkyl, alkenyl, alkynyl, alkylenedioxy, haloalkylenedioxy, cycloalkyl, cycloalkenyl, lower cycloalkylalkyl, lower cycloalkenylalkyl, halo, haloalkyl, haloalkoxy, hydroxyhaloalkyl, hydroxyaralkyl, hydroxyalkyl, hydoxyheteroaralkyl, haloalkoxyalkyl, aryl, aralkyl, aryloxy, aralkoxy, aryloxyalkyl, saturated heterocyclyl, partially saturated heterocyclyl, heteroaryl, heteroaryloxy, heteroaryloxyalkyl, arylalkyl, heteroarylalkyl, arylalkenyl, heteroarylalkenyl, cyanoalkyl, dicyanoalkyl, carboxamidoalkyl, dicarboxamidoalkyl, cyanocarboalkoxyalkyl, carboalkoxyalkyl, dicarboalkoxyalkyl, cyanocycloalkyl, dicyanocycloalkyl, carboxamidocycloalkyl, dicarboxamidocycloalkyl, carboalkoxycyanocycloalkyl, carboalkoxycycloalkyl, dicarboalkoxycycloalkyl, formylalkyl, acylalkyl, dialkoxyphosphonoalkyl, diaralkoxyphosphonoalkyl, phosphonoalkyl, dialkoxyphosphonoalkoxy, diaralkoxyphosphonoalkoxy, phosphonoalkoxy, dialkoxyphosphonoalkylamino, diaralkoxyphosphonoalkylamino, phosphonoalkylamino, dialkoxyphosphonoalkyl, diaralkoxyphosphonoalkyl, guanidino, amidino, and acylamino. In another embodiment, the present invention provides treatment utilizing a compound or a salt thereof, the compound having a structure corresponding to Formula II:

In the structure of Formula II, X is selected from the group consisting of -S-, -S(O)-, and -S(O)₂-. Preferably, X is -S-. R¹² is selected from the group consisting of - alkyl, C₂-C₆ alkenyl, C₂-C₆ alkynyl, -C₅ alkoxy- alkyl, and -C₅ alkylthio- alkyl wherein each of these groups is optionally substituted by one or more substituent selected from the group consisting of -OH, alkoxy, and halogen. Preferably, R¹² is C C₆ alkyl optionally substituted with a substituent selected from the group consisting of -OH, alkoxy, and halogen. With respect to R and R , R is selected from the group consisting of -OR and -N(R²⁵)(R²⁶), and R¹³ is selected from the group consisting of -H, -OH, -C(O)-R²⁷, -C(O)-O-

R >28 , and -C(O)-S-R .2"9;. or R .1^l8^δ is -N(R , 3^J0 , and R 1¹3^J . is -C(O)-, wherein R , 1^l8^δ a . nd R , 1¹3 ^> . together with the atoms to which they are attached form a ring; or R is -O-, and R is -C(R )(R )-, wherein R¹⁸ and R¹³ together with the atoms to which they are attached form a ring. If R¹³ is -C(R3²¹)(R³²)-, then R¹⁴ is -C(O)-O-R³³; otherwise R¹⁴ is -H. R¹¹, R¹⁵, R¹⁶, and R¹⁷ independently are selected from the group consisting of -H, halogen, Cι-C₆ alkyl, C₂-C₆ alkenyl, C₂-C₆ alkynyl, and -C₅ alkoxy-Ci alkyl. R¹⁹ and R²⁰ independently are selected from the group consisting of -H, Ci-C₆ alkyl, C₂-C₆ alkenyl, C₂-C₆ alkynyl, and C₁-C₅ alkoxy- alkyl. With respect to R²¹ and R²², R²¹ is selected from the group consisting of -H, -OH, -C(O)-O-R³⁴, and -C(O)-S-R³⁵, and R²² is selected from the group consisting of -H, -OH, -C(O)-O-R³⁶, and -C(O)-S-R³⁷; or R²¹ is -O-, and R²² is -C(O)-, wherein R²¹ and R²² together with the atoms to which they are attached form a ring; or R²¹ is -C(O)-, and R²² is - 1 99 TX

O-, wherein R and R together with the atoms to which they are attached form a ring. R is C_\ alkyl. R²⁴ is selected from the group consisting of -H and -C alkyl, wherein when R²⁴ is Ci-Cg alkyl, R²⁴ is optionally substituted by one or more moieties selected from the group consisting of cycloalkyl, heterocyclyl, aryl, and heteroaryl. With respect to R²⁵ and

9β 9*! Λ

R , R is selected from the group consisting of -H, alkyl, and alkoxy, and R is selected from the group consisting of -H, -OH, alkyl, alkoxy, -C(O)-R³⁸, -C(O)-O-R³⁹, and -C(O)-S- R⁴⁰; wherein when R²⁵ and R²⁶ independently are alkyl or alkoxy, R²⁵ and R²⁶ independently are optionally substituted with one or more moieties selected from the group consisting of cycloalkyl, heterocyclyl, aryl, and heteroaryl; or R²⁵ is -H; and R²⁶ is selected from the group consisting of cycloalkyl, heterocyclyl, aryl, and heteroaryl. R²⁷, R²⁸, R²⁹, R³⁰, R³¹, R³², R³³, R³⁴, R³⁵, R³⁶, R³⁷, R³⁸, R³⁹, and R⁴⁰ independently are selected from the group consisting of - H and alkyl, wherein alkyl is optionally substituted by one or more moieties selected from the group consisting of cycloalkyl, heterocyclyl, aryl, and heteroaryl. When any of R¹¹, R¹², R¹³, R¹⁴, R¹⁵, R¹⁶, R¹⁷, R¹⁸, R19⁹, R²⁰, R²¹, R²², R²³, R²⁴, R²⁵, R²⁶, R²⁷, R²⁸, R²⁹, R³⁰, R³¹, R³², R³³, R³⁴, R³⁵ R³⁶, R³⁷, R³⁸, R³⁹, and R⁴⁰ independently is a moiety selected from the group consisting of alkyl, alkenyl, alkynyl, alkoxy, alkylthio, cycloalkyl, heterocyclyl, aryl, and heteroaryl, then the moiety is optionally substituted by one or more substituent selected from the group consisting of -OH, alkoxy, and halogen.

In a preferred compound, R¹⁸ is -OH. When R¹⁸ is -OH, preferably X is S. In a further compound, Rⁿ, R¹⁵, R¹⁶, R¹⁷, R¹⁹, and R²⁰ independently are selected from the group consisting of -H and C1-C3 alkyl. Preferably R¹⁵, R¹⁶, R¹⁷, R¹⁹, R²⁰ each are -H. R²³ can be a variety of groups, for example fluoromethyl or methyl. R¹¹ can be Ci-C₆ alkyl optionally substituted with a substituent selected from the group consisting of -OH and halogen; preferably R^π is Ci alkyl optionally substituted with halogen; more preferably R^{1 ]} is selected from the group consisting of fluoromethyl, hydroxyrnethyl, and methyl. In one important compound, R^π can be methyl. Alternatively, R¹¹ can be fluoromethyl. In another alternative R¹¹ can be hydroxyrnethyl. In another compound, R¹² is -C₆ alkyl optionally substituted with a substituent selected from the group consisting of -OH, alkoxy, and halogen, hi one

19 * 19 preferred compound R is C_ alkyl optionally substituted with halogen. For example, R can be methyl. Alternatively, R¹² can be fluoromethyl. In yet another example, R¹² can be hydroxyrnethyl. In still another example, R¹² can be methoxymethyl.

■ 1 ^ 14 1 99

In this exemplary compound, it is preferred that R , R , R and R each is -H. hi this compound, it is further preferred that R¹¹, R¹⁵, R¹⁶, R¹⁷, R¹⁹, and R²⁰ independently are selected from the group consisting of -H and C₁-C₃ alkyl. Preferably R¹⁵, R¹⁶, R¹⁷, R¹⁹, R²⁰ each is -H. In this further compound, R can be, for example, fluoromethyl, or in another example R²³ can be methyl. In preferred compounds of these examples, R¹² is Ci-C₆ alkyl optionally substituted with a substituent selected from the group consisting of -OH, alkoxy,

19 " • and halogen. Preferably R is Ci alkyl optionally substituted with halogen, hi one such

19 * 1 19 example R is fluoromethyl. In another example R is methyl. Alternatively R can be hydroxyrnethyl. In another alternative, R¹² can be methoxymethyl.

When R²³ is methyl, Rⁿ can be, for example, -H or -Ce alkyl optionally substituted with a substituent selected from the group consisting of -OH and halogen, h a preferred compound R¹¹ is -H. Alternatively, R¹¹ can be Ci-C_δ alkyl optionally substituted with a substituent selected from the group consisting of -OH and halogen. For example R^u can be methyl, ethyl, n-propyl, i-propyl, n-butyl, sec-butyl, isobutyl, t-butyl, a pentyl isomer, or a hexyl isomer. For example, R¹¹ can be ethyl. Alternatively, R¹¹ can be Ci alkyl optionally substituted with a substituent selected from the group consisting of -OH and halogen; for example R¹¹ can be methyl. Alternatively, R¹¹ can be fluoromethyl. In another alternative, R¹¹ can be hydroxyrnethyl.

In another compound R¹⁸ can be -OR²⁴. R²⁴ can be as defined above. Preferably R²⁴ is -C₆ alkyl optionally substituted by one or more moieties selected from the group consisting of cycloalkyl, heterocyclyl, aryl, and heteroaryl; more preferably R²⁴ is C C₃ alkyl; and more preferably still R²⁴ is methyl. In yet another example of compound II, R¹⁸ can be -N(R²⁵)(R²⁶), wherein R²⁵ and R²⁶ are as defined above. In still another compound, R¹⁸ can be -N(R³⁰)-, and R¹³ can be -C(O , wherein R¹⁸ and R¹³ together with the atoms to which they are attached form a ring. In another example still, R¹⁸ can be -O-, and R¹³ can be -C(R³¹)(R³²)-, wherein R¹⁸ and R¹³ together with the atoms to which they are attached form a ring. In a compound of Formula II, R²¹ can be selected from the group consisting of -OH, -C(O)-O-R³⁴, and -C(O)-S-R³⁵. Preferably R²¹ is -OH. hi a further example, R²² is -H when R²¹ is -OH.

However, the present example also provides useful compounds of Formula II in which R²¹ is -O-, and R²² is -C(O)-, wherein R²¹ and R²² together with the atoms to which

91 99 they are attached form a ring. In another useful compound, R is -C(O)-, and R is -O-, wherein R²¹ and R²² together with the atoms to which they are attached form a ring. Alternatively, R²² can be selected from the group consisting of -OH, -C(O)-O-R³⁶, and - C(O)-S-R³⁷. hi this alternative, R²¹ is preferably -H.

In another selective iNOS inhibitor useful in the practice ofthe present mvention, a compound is represented by Formula III:

or a pharmaceutically acceptable salt thereof, wherein:

R ,41 is H or methyl; and

R .42 is H or methyl.

Another selective iNOS inhibitor useful in the practice ofthe present invention is represented by a compound of formula IV

IV or a pharmaceutically acceptable salt thereof. Another exemplary selective iNOS inhibitor useful in the present invention is represented by Formula V:

or a pharmaceutically acceptable salt thereof, wherein:

R⁴³ is selected from the group consisting of hydrogen, halo, -Cs alkyl and Cι-C₅ alkyl substituted by alkoxy or one or more halo;

R⁴⁴ is selected from the group consisting of hydrogen, halo, -C₅ alkyl and Ci-C₅ alkyl substituted by alkoxy or one or more halo;

R⁴⁵ is -C₅ alkyl or -C₅ alkyl be substituted by alkoxy or one or more halo.

A further illustrative selective iNOS inhibitor is represented by Formula VI:

VI or a pharmaceutically acceptable salt thereof, wherein:

R⁴⁶ is Cι-C₅ alkyl, said -C5 alkyl optionally substituted by halo or alkoxy, said alkoxy optionally substituted by one or more halo. Another exemplary selective iNOS inhibitor useful in the present invention is represented by Formula VII

VII

or a pharmaceutically acceptable salt thereof, wherein:

R⁴⁷ is selected from the group consisting of hydrogen, halo, Ci-C₅ alkyl and -C₅ alkyl substituted by alkoxy or one or more halo;

R⁴⁸ is selected from the group consisting of hydrogen, halo, C₁-C5 alkyl and -Cs alkyl substituted by alkoxy or one or more halo;

R⁴⁹ is -C₅ alkyl or C₁-C₅ alkyl be substituted by alkoxy or one or more halo.

Another exemplary selective iNOS inhibitor useful in the present invention is represented by Formula VHI

VIII or a phaπnaceutically acceptable salt thereof, wherein:

R⁵⁰ is -C5 alkyl, said -C₅ alkyl optionally substituted by halo or alkoxy, said alkoxy optionally substituted by one or more halo. Another selective iNOS inhibitor useful in the practice ofthe present invention is represented by a compound of formula IX

IX or a pharmaceutically acceptable salt thereof, wherein:

R⁵⁰ is selected from the group consisting of hydrogen, halo, and -Cs alkyl, said C_\-

R⁵¹ is selected from the group consisting of hydrogen, halo, and -Cs alkyl, said C_\-

R⁵² is -C₅ alkyl, said C Cs alkyl optionally substituted by halo or alkoxy, said alkoxy optionally substituted by one or more halo;

R is selected from the group consisting of hydrogen, halo, andCι-C₅ alkyl, said -

R⁵⁴ is selected from the group consisting of halo and -C₅ alkyl, said C₁-C₅ alkyl optionally substituted by halo or alkoxy, said alkoxy optionally substituted by one or more halo.

Yet another selective iNOS inhibitor useful in the practice ofthe present invention is represented by a compound of formula X

X or a pharmaceutically acceptable salt thereof, wherein:

R⁵⁵ is Cι-C₅ alkyl, said -C₅ alkyl optionally substituted by halo or alkoxy, said alkoxy optionally substituted by one or more halo.

b. Illustrative Examples

The following synthesis examples are shown for illustrative purposes and in no way intended to limit the scope of the invention. Where isomers are not defined, utilization of appropriate cliromatography methods will afford single isomers.

Example A

(2S,5E)-2-amino-6-fluoro-7-[(l-iminoethyl)amino]-5-heptenoic acid, dihydrochloride, monohydrate

NH-Boc

CH₃

O O

EX-A-1) Trimethylsilyl chloride (107.8 g, 1.00 mol) was added dropwise to a cooled solution of L-glutamic acid (30.00 g, 0.20 mol) in 300 mL of methanol at 0 °C. The resulting clear, colorless solution was allowed to stir at room temperature. After 18 h, analysis by thin layer chromatography (30% ethyl acetate in hexane) showed that no starting material remained. The reaction was then cooled to 0 °C, triethylamine (134 g, 1.33 mol) was added, and a white precipitate formed. Di-tert-butyldicarbonate (49 g, 0.23 mol) was added, and the mixture was allowed to warm to room temperature. After 3 h the solvent was removed, and 700 mL of diethyl ether was added. The solution was filtered, and the filter cake was rinsed with an additional 500 mL of diethyl ether. The filtrate was concentrated to 60.8 g (>95%) of a tan oil which was carried onto the next step without further purification. LCMS: m/z = 298.1 [M+Na . HRMS calcd. for Cι₂H₂₁NO₆: 276.1447 [M+H]⁺, found: 276.1462. 1H NMR (CDC1₃) ? 1.45 (s, 9H), 1.95 (m, IH), 2.50 (m, IH), 2.40 (m, 2H), 3.69 (s, 3H), 3.75 (s, 3H), 4.32 (m, IH), 5.15 (m, IH).

N(Boc)₂

CH,

O O

EX-A-2) To a solution ofthe crude product from EX-A-1 (60 g, 0.22 mol) in 300 mL of acetonitrile at room temperature was added 4-dimethylaminopyridine (5.3 g, 0.44 mol) and di-tert-butyldicarbonate (79.2 g, 0.36 mol). The resulting mixture was stirred for 2 days at room temperature, at which time analysis by thin layer chromatography (25% ethyl acetate in hexane) showed that most ofthe starting material was consumed. The solvent was removed in vacuo affording 85 g of a red oil. The crude material was purified by flash column chromatography on silica gel eluting with 1:10 ethyl acetate in hexane to give 66.4 g (81%) ofthe desired di-Boc product as a pale-yellow solid. LCMS: m/z = 398.2 [M+Na]⁺. HRMS calcd. for C₁₇H₂₉NO₈: 398.1791 [M+Na , found: 398.1790. 1H NMR (CDC1₃) ? 1.48 (s, 18H), 2.19 (m, IH), 2.41 (m, 2H), 2.46 (m, IH), 3.66 (s, 3H), 3.70 (s, 3H), 4.91 (dd, IH).

EX-A-3) A solution of DIBAL (64 mL of 1.0 M solution in hexanes, 63.9 mmol) was added dropwise to a cold solution of EX-A-2 (20 g, 53.3 mmol) in 400 mL of anhydrous diethyl ether at -78 °C over 30 min. After an additional 30 min at -78 °C, the solution was quenched with water (12 mL, 666 mmol) and allowed to warm to room temperature. The cloudy mixture was diluted with 350 mL of ethyl acetate, dried over MgSO₄ and filtered through a pad of celite. The filtrate was concentrated to a yellow oil. The crude material, 18.9 g of yellow oil, was purified by flash column chromatography on silica gel eluting with 1 :4 ethyl acetate in hexane to give 13.8 g (75%) ofthe desired aldehyde product as a clear oil. LCMS: m/z = 368.2 [M+Na]⁺. 1H NMR (CDC1₃) ? 1.48 (s, 18H), 2.19 (m, IH), 2.41 (m, 2H), 2.46 ( , IH), 3.70 (s, 3H), 4.91 (dd, IH), 9.8 (s, IH).

EX-A-4) To a cold (-78 °C) solution of triethyl 2-fluoroρhosphonoacetate (4.67 g, 19.3 mmol) in 20 mL of THF was added n-butyl lithium (10.9 mL of 1.6 M in hexane, 17.5 mmol). This mixture was stirred at -78 °C for 20 min producing a bright yellow solution. A solution ofthe product from EX-A-3 (6.0 g, 17.5 mmol) in 5 mL of THF was then added via syringe, and the resulting mixture was stirred for 2 h at -78 °C, at which time analysis by thin layer chromatography (30% ethyl acetate in hexane) showed that no starting material remained. The reaction was quenched at -78 °C with sat. aqueous NH₄C1 (30 mL). The organic layer was collected, and the aqueous layer was extracted with diethyl ether (2 x 50 mL). The combined organics were washed with water (100 mL) and brine (100 mL), dried over MgSO₄, filtered and concentrated. The crude material, 8.6 g of a yellow oil, was purified by flash column chromatography on silica gel eluting with 1 :4 ethyl acetate in hexane to give 6.05 g (79%) ofthe desired fluoro olefin product as a clear oil. 1H NMR and ¹⁹F NMR indicated that the isolated product had an approximate E:Z ratio of 95:5. LCMS: m/z = 456.2 [M+Naf. HRMS calcd. for C₂₀H₃₂NO₈F: 456.2010 [M+Naf, found: 456.2094. 1H NMR (CDC1₃) ? 1.48 (s, 18H), 2.0 (m, IH), 2.25 (m, IH), 2.6 (m, 2H), 3.7 (s, 3H), 4.25 (m, 2H), 4.9 (m, IH), 5.9 (dt, vinyl, IH, J= 20 Hz), 6.2 (dt, vinyl, IH, J= 30 Hz). ¹⁹F NMR (CDC1₃) ? -129.12 (d, 0.09F, J= 31 Hz, 9% Z-isomer), -121.6 (d, 0.91F, J= 20 Hz, 91% E-isomer).

EX-A-5) To a solution of EX-A-4 (805 mg, 1.86 mmol) in 20 mL of methanol at room temperature was added solid NaBH (844 mg, 22.3 mmol) in 200 mg portions. The reaction was stirred for 18 h at ambient temperature, at which time analysis by thin layer chromatography (30% ethyl acetate in hexane) showed that most ofthe starting material was consumed. The reaction was quenched with 20 mL of sat. aqueous NH₄C1 and extracted with ethyl acetate (2 x 35 mL). The organic layers were combined, dried over MgSO₄, filtered and concentrated. The crude material, 700 mg of clear oil, was purified by flash column chromatography on silica gel eluting with 1 :4 ethyl acetate in hexane to give 353 mg (48%) ofthe desired allylic alcohol product as a clear oil, that contained primarily the desired E- isomer by ¹⁹F NMR. LCMS: m/z = 414.2 [M+Naf. 1H NMR (CDC1₃) ? 1.48 (s, 18H), 1.95 (m, IH), 2.1 (m, IH), 2.2 (m, IH), 2.35 (t, IH), 3.7 (s, 3H), 4.25 (m, 2H), 4.8 (m, IH), 5.15 (dt, IH, J= 20 Hz). ¹⁹F NMR (CDCI3) ? -119.1 (d, 0.02F, J= 37 Hz, 2% Z-isomer), -111.8 (d, 0.98F, J= 24 Hz, 98% E-isomer).

EX-A-6) To a mixture of EX-A-5 (1.37 g, 3.5 mmol), polymer-supported triphenylphosphine (3 mmol/g, 1.86 g, 5.6 mmol) and 3-methyl-l,2,4-oxadiazolin-5-one (450 mg, 4.55 mmol) in 50 mL of THF was added dropwise dimethylazodicarboxylate (820 mg, 5.6 mmol). The reaction was stirred for 1 h at room temperature, at which time analysis by thin layer chromatography (40% ethyl acetate in hexane) showed that no starting material remained. The mixture was filtered through celite^ and the filtrate was concentrated. The resulting yellow oil was partitioned between 30 mL of methylene chloride and 30 mL of water. The organic layer was separated, washed with water (1 x 30 mL) and brine (1 x 30 mL), dried over MgSO₄, filtered and concentrated. The crude material, 1.8 g of a yellow oil, was purified by flash column chromatography on silica gel eluting with 1 :4 ethyl acetate in hexane to give 670 mg (40%) ofthe desired protected E-allylic amidine product as a clear oil, that contained only the desired E-isomer by ¹⁹F NMR. LCMS: m/z = 496.2 [M+Naf. 1H NMR (CDC1₃) ? 1.48 (s, 18H), 1.85 (m, IH), 2.2 (m, 3H), 2.25 (s, 3H), 3.64 (s, 3H), 4.25 ( , 2H), 4.8 (m, IH), 5.3 (dt, IH, J= 20 Hz). ¹⁹F NMR (CDC1₃) ? -110.8 (q, IF, J= 20 Hz).

EX-A-7) The product from EX-A-6 (670 mg, 1.4 mmol) was dissolved in 25 mL of methanol and 25 mL of 25% acetic acid in water. Zinc dust (830 mg, 12.7 mmol) was added, and the mixture was agitated under sonication for 8 h, at which time HPLC analysis showed that only 20% ofthe starting material remained. The Zn dust was filtered from the reaction mixture, and the filtrate was stored at -20 °C for 12 h. The filtrate was warmed to room temperature, additional glacial acetic acid (7 mL) and zinc dust (400 mg, 6.1 mmol) were added, and the mixture was sonicated for 1 h at room temperature, at which time HPLC analysis showed 96% product. The mixture was filtered through celite, and the filtrate was concentrated. The crude material was purified by reverse-phase HPLC column chromatography on a YMC Combiprep column eluting over 8 min using a gradient of 20- 95% A (A: 100% acetonitrile with 0.01% trifluoroacetic acid, B: 100% H₂O with 0.01% trifluoroacetic acid). Fractions containing product were combined and concentrated affording 344 mg (45%) ofthe desired acetamidine product as a trifluoroacetate salt, that contained only the desired E-isomer by ¹⁹F NMR. LCMS: m/z = 432.3 [M+H]⁺. 1H NMR (CD₃OD) ? 1.52 (s, 18H), 2.9 (m, IH), 2.2 (m, 3H), 2.27 (s, 3H), 4.2 (d, IH), 5.4 (dt, vinyl, IH, J= 20 Hz). ¹⁹F NMR (CD₃OD) ? -110.83 (m, IF, J= 20 Hz).

EX-A-8) A sample ofthe product of EX-A-7 is dissolved in glacial acetic acid. To this stirred solution is added 10 equivalents of IN HCl in dioxane. After stirring this solution for ten minutes at room temperature, all solvent is removed in vacuo to generate the illustrated methyl ester dihydrochloride salt.

Example A) A solution of EX-A-7 (344 mg, 1.4 mmol) in 6 mL of 6.0 N HCl was refluxed for 1 h. The solvent was removed in vacuo. The resulting solid was dissolved in water and concentrated three additional times, followed by 5 subsequent times in 1.0 N HCl to remove any remaining TFA salts. Upon completion, 160 mg (37%) ofthe desired (2S,5E)-2-amino- 6-fluoro-7-[(l-iminoethyl)amino]-5-heptenoic acid, dihydrochloride product was obtained as a white solid, m.p. 51.5-56.3 °C, that contained only the desired Ε-isomer by ¹⁹F NMR. LCMS: m/z = 218.1 [M+Hf. HRMS calcd. for C₉H₁₆FN₃O₂: 218.1305 [M+H]⁺, found: 218.1325. 1H NMR (D₂O) ? 1.8 (m, 2H), 2.05 (m, 2H), 2.1 (s, 3H), 3.7 (t, IH), 4.00 (d, 2H), 5.3 (dt, vinyl, IH, J= 21 Hz). ¹⁹F NMR (D₂O) ? -109.9 (m, IF, J= 20 Hz). Example B

(2S,5i?/-Z)-2-amino-6-fluoro-7-[(l-immoethyl)amino]-5---ιeptenoic acid, dihydrochloride

NH-Boc

EX-B-1) To a cooled (0 °C) solution of L-glutamic acid 5-methyl ester (50.00 g, 0.31 mol) in 400 mL of 1 : 1 H₂O in dioxane was added triethylamine (38.35 g, 0.38 mol) followed by di-tert-butyldicarbonate (80.00 g, 0.37 mol). The resulting clear, colorless solution was allowed to stir at room temperature. After 18 h, analysis by thin layer chromatography (30% ethyl acetate in hexane) showed that no starting material remained. The reaction mixture was quenched with 200 mL of 1.0 N aqueous KHSO₄. The organic layer was removed, and the aqueous layer was extracted with ethyl acetate (3 x 100 mL). The organic layers were combined, dried over MgSO₄, filtered and concentrated to give 72.00 g (89%) ofthe desired product as a pale yellow oil. LCMS: m/z = 284.1 [M+Naf. ^!H NMR (CDC1₃) ? 1.50 (s, 9H), 2.00 (m, IH), 2.20 (m, IH), 2.42 (m, 2H), 3.66 (s, 3H), 4.34 (d, IH), 5.24 (d, IH).

NH-Boc

EX-B-2) To a solution ofthe product from EX-B-1 (72.60 g, 0.28 mol) in 300 mL of THF at -10 °C was quickly added 4-methylmorpb.oline (28.11 g, 0.28 mol) and isobutylchloroformate (37.95 g, 0.28 mol). The clear yellow solution immediately formed a white precipitate. After 4 min, the resulting cloudy yellow mixture was filtered, the filtrate was cooled to -10 °C and a solution of NaBH₄ (15.77 g, 0.42 mol) in 200 mL of H₂O was added dropwise while maintaining a subzero temperature. Once all ofthe NaBH₄ was added, the ice bath was removed, and the reaction was allowed to stir at room temperature for 1.5 h. The reaction mixture was quenched with 200 mL of H₂O. The organic layer was separated, and the aqueous layer was extracted with ethyl acetate (3 x 100 mL). The organic layers were combined, washed with brine, dried over MgSO₄, filtered and concentrated to give 58 g (85%) ofthe desired product as a yellow oil. LCMS: m/z = 270.1 [M+Naf. 1H NMR (CDC1₃) ? 1.42 (s, 9H), 1.65 (m, IH), 1.85 (m, 2H), 2.42 (t, 2H), 3.66 (s, 3H), 4.8 (d, IH).

EX-B-3) To a solution of EX-B-2 (30.95 g, 0.13 mol) in 100 mL of benzene was added 2,2- dimethoxy propane (65.00 g, 0.63 mol) followed by ^-toluenesulfonic acid (2.40 g, 12.5 mmol) and 5 g of 3 A molecular sieves. The resulting mixture was refluxed for 2 h, at which time analysis by thin layer chromatography (30% ethyl acetate in hexane) showed complete reaction. The mixture was cooled to room temperature, diluted with diethyl ether (150 mL) and washed with sat. aqueous NaHCO₃ (100 mL) followed by brine (100 mL). The organic layer was dried over MgSO₄, filtered and concentrated. The crude material, 30.5 g of a yellow oil, was purified by flash column chromatography on silica gel eluting with 1:10 ethyl acetate in hexane to give 15.40 g (42%) ofthe desired product as a pale-yellow oil. LCMS: m/z = 310.1 [M+Naf. 1H NMR (CDCI₃) ? 1.42 (s, 12H), 1.56 (d, 3H), 1.85 (m, 2H), 2.38 (m, 2H), 3.66 (s, 3H), 3.7 (d, IH), 3.95 (m, 2H).

EX-B-4) DIBAL (6.0 mL of 1.0 M solution in toluene) was added dropwise to a cold (-78 °C) solution of the product from EX-B-3 (1.00 g, 3.00 mmol) in 10 mL of methylene chloride. After 30 min, the reaction was quenched with 5 mL sat. potassium sodium tartrate (Rochelle salt), then allowed to warm to room temperature. The mixture was then filtered through a pad of celite, dried over MgSO₄, re-filtered and concentrated to give a yellow oil. The crude material, 610 mg of a yellow oil, was purified by flash column chromatography on silica gel eluting with 1 :4 ethyl acetate in hexane to give 550 mg (71%) ofthe desired product as a clear oil. 1H NMR (CDC1₃) ? 1.50 (s, 12H), 1.58 (d, 3H), 2.00 (m, 2H), 2.5 (m, 2H), 3.7 (d, IH), 3.95 (m, 2H), 9.8 (s, IH).

EX-B-5) To an ice cold (0 °C) solution of triethyl 2-fluoro-phosphonoacetate (6.70 g, 27.6 mmol) in 100 mL of methylene chloride was added l,8-diazabicyclo[5.4.0]undec-7-ene (4.70 g, 31.0 mmol). The mixture was stfrred at 0 °C for 1 h resulting in an orange solution. Then, a ice cold (0 °C) solution ofthe product from EX-B-4 (5.71 g, 22.2 mmol) in 15 mL of methylene chloride was added via syringe, and the resulting mixture was stirred for 18 h at ambient temperature, at which time analysis by thin layer chromatography (30% ethyl acetate in hexane) showed that no starting material remained. The solvent was removed in vacuo, and the resulting mixture was partitioned between 200 mL of ethyl acetate and 100 mL of water. The organic layer was collected, and the aqueous layer was extracted with ethyl acetate (2 x 50 mL). The combined organic layers were washed with 1.0 M aqueous KHSO₄ (100 mL), water (100 mL) and brine (100 mL), dried over MgSO₄, filtered and concentrated to give the desired fluoro olefin product as a yellow oil (8.0 g). H NMR and ¹⁹F NMR indicated that the isolated product had an approximate Z:E ratio of 70:30. LCMS: m/z = 368.2 [M+Naf. 1H NMR (CDC1₃) ? 5.9-6.0 (dt, IH, J= 20 Hz), 6.05-6.20 (dt, IH, J= 33 Hz). ¹⁹F NMR (CDCI₃) ? -129.89 (d, 0.7F, J= 38 Hz, 70% Z-isomer), -122.05 (d, 0.3F, J= 20 Hz, 30% E-isomer). This mixture was carried on crude without further purification.

EX-B-6) To an ice cold (0 °C) solution ofthe product from EX-B-5 (8.0 g, 23.0 mmol) in 70 mL of THF was added LiBH₄ (12.7 mL of 2.0 M in THF, 25.0 mmol) via syringe. The reaction mixture was stirred for 18 h at ambient temperature at which time analysis by thin layer chromatography (30% ethyl acetate in hexane) showed that no starting material remained. The THF was removed, and the resulting mixture was dissolved in methylene chloride. After cooling to 0 °C, 1.0 M aqueous KHSO₄ was slowly added to quench the reaction. The mixture was then extracted with ethyl acetate (3 x 50 mL). The organic layers were combined, dried over MgSO₄, filtered and concentrated. The crude material, 8.0 g of a clear oil, was purified by flash column chromatography on silica gel eluting with 1 :4 ethyl acetate in hexane to give 900 mg (13%) ofthe desired product as a clear oil. LCMS: m/z = 326.2 [M+Naf. 1H MR (CDC1₃) ? 4.79-4.94 (dm, IH), 5.10-5.25 (dt, IH). ¹⁹F NMR (CDCI₃) ? -119.82 (dt, 0.7F, J= 38 Hz, 70% Z-isomer), -111.09 (dt, 0.3F, J= 27 Hz, 30% E- isomer).

EX-B-7) To an ice cold (0 °C) solution ofthe product from EX-B-6 (950 mg, 3.1 mmol) in 5 mL of pyridine was added methanesulfonyl chloride (390 mg, 3.4 mmol). The reaction was stirred for 5 min at 0 °C, then warmed to room temperature and stirred for 3 h, at which time analysis by thin layer chromatography (30% ethyl acetate in hexane) showed that no starting material remained. The reaction was diluted with diethyl ether (10 mL) and washed with sat. aqueous NaHCO₃ (20 mL) followed by 1.0 M citric acid (20 mL). The organic layer was dried over MgSO , filtered and concentrated to give 500 mg (51%) ofthe desired allylic chloride product as a white solid. This product was carried forward without further purification. LCMS: m/z = 344.1 [M+Naf.

EX-B-8) To a stirring solution ofthe product from EX-B-7 (440 mg, 1.37 mmol) in 10 mL of DMF was added potassium phthalimide (290 mg, 1.57 mmol). The resulting mixture was heated under reflux for 18 h, at which time analysis by thin layer chromatography (30% ethyl acetate in hexane) showed that no starting material remained. The cooled mixture was diluted with 30 mL of water, extracted twice with ethyl acetate (30 mL), dried over MgSO , filtered and concentrated to give 540 mg (91%) ofthe desired product as a yellow oil. LCMS: m/z = 455.2 [M+Naf. HRMS calcd. for : 433.2139 [M+H]⁺, found: 433.2144. 1H NMR (CDC1₃) ? 1.4 (s, 18H), 1.6 (m, 6H), 2.05 (m, 2H), 3.6-4.42 (m, 4H), 4.9 (dt, vinyl, IH), 5.2, (m, vinyl, IH), 7.7 (m, 2H), 7.9 (m, 2H). ¹⁹F NMR (CDC1₃) ? -117.09 (m, 0.7F, J= 38 Hz, 70% Z-isomer), -111.61 (m, 0.3F, J- 22 Hz, 30% E-isomer).

EX-B-9) The product from EX-B-8 (600 mg, 1.38 mmol) was dissolved in 8 mL of acetic acid and 2 mL of water. The mixture was stirred at room temperature overnight at which time analysis by thin layer chromatography (30% ethyl acetate in hexane) showed that no starting material remained. The solution was concentrated under a stream of nitrogen, and the crude product was purified by flash column chromatography on silica gel eluting with 1 :2 ethyl acetate in hexane to give 248 mg (63%) ofthe desired product as a white solid. LCMS: m/z = 415.1 [M+Naf. 1H NMR (CDC1₃) ? 1.41 (s, 9H), 1.56 (m, 2H), 2.15 (m, IH), 3.64 (m, 2H), 4.35 (d, 2H), 4.9 (dt, vinyl, IH, J= 37 Hz), 7.73 (m, 2H), 7.86 (m, 2H). ¹⁹F NMR (CDC1₃) ? -116.96 (dt, 0.8F, J= 37 Hz, 80% Z-isomer), -111.09 (dt, 0.2F, J= 22 Hz, 20% E- isomer).

EX-B-10) To a stirring solution ofthe product from EX-B-9 (237 mg, 0.605 mmol) in 6 mL of DMF was added pyridinium dichromate (1.14 g, 3.03 mmol). The solution turned dark orange and was allowed to stir at room temperature for 18 H, at which time it was poured into 20 mL of H₂O. The mixture was extracted with ethyl acetate (4 x 25 mL). The combined organic layers were washed with 5% aqueous KHCO₃ (3 x 25 mL). The aqueous layer was acidified with 1.0 M KHSO₄ to pH=3 followed by extraction with ethyl acetate (3 x 50 mL). The combined organic layers were concentrated to yield 235 mg (95%) ofthe desired amino acid product. The resulting white solid was carried on crude without further purification. LCMS: m/z = 429.1 [M+Naf.

EX-B-11) To stirring solution of the product from EX-B-10 (230 mg, 0.56 mmol) in 7 mL of ethanol was added hydrazine hydrate (70 mg, 1.13 mmol), and the resulting solution was refluxed for 2 h forming a white precipitate. The solvent was removed in vacuo. The resulting white solid was dissolved in 8 mL of water and acidified to pH=4 with glacial acetic acid. It was then cooled in an ice bath and filtered. The filtrate was concentrated to give 136 mg (87%) ofthe desired allyl amine product as yellow crystals which were carried onto the next step without purification. LCMS: m/z = 277.1 [M+H]⁺.

EX-B-12) To a stirring solution ofthe product from EX-B-11 (136 mg, 0.50 mmol) in 6 mL of DMF was added ethyl acetimidate (252 mg, 2.04 mmol) in 3 portions over 1.5 h intervals. After the addition was complete, the mixture was stirred overnight at room temperature. The pink solution was filtered, and the filter cake was washed with water. The solvent was removed in vacuo, and the resulting yellow oil was purified by reverse-phase HPLC using a YMC Combiprep ODS-A semi-prep column eluting with a 7 minute gradient of 1-50% A (A: 100 acetonitrile with 0.05% TFA, B: 100 water with 0.05% TFA). Fractions containing product were combined and concentrated to afford approximately 50 mg ofthe desired acetamidine product as a trifluoroacetate salt which was carried onto the next step. LCMS:

Example B) The product from EX-B-12 was dissolved in 6 mL of 6.0 N HCl and stirred for 1 h at room temperature. The solvent was removed in vacuo. The resulting solid was dissolved in water and concentrated three additional times to remove TFA salts. When ¹⁹F NMR indicated that all ofthe TFA was removed, the product was dried in vacuo to give 30 mg (20%, combined yield over two steps) of a 20:80 E:Z mixture containing the desired (2S,5E)-2-amino-6-fluoro-7-[(l-iminoethyl)amino]-5-heptenoic acid, dihydrochloride and (2S,5Z)-2-amino-6-fluoro-7-[(l-iminoethyl)amino]-5-heptenoic acid, dihydrochloride as a foamy clear solid. HRMS calcd. for C₉H₁₆FN₃O₂: 218.1305 [M+H]⁺, found: 218.1309. 1H NMR (D₂O) ? 2.01 (m, 2H), 2.21 (s, 3H), 2.24 (m, 2H), 3.96 (t, IH), 4.00 (d, 2H), 5.07 (dt, vinyl, IH, J= 37 Hz), 5.4 (dt, vinyl, IH, J= 37 Hz). ¹⁹F NMR (D₂O) ? -116.8 (m, 0.8F, J= 37 Hz, 80% Z-isomer), -109.6 (m, 0.2F, J= 21 Hz, 20% Ε-isomer). Example C

(2S,5Z)-2-amino-6-fluoro-7-[(l-iminoethyl)amino]-5-heptenoic acid, dihydrochloride

EX-C-1) Triethyl 2-fluoro-phosphonoacetate (3.54 g, 14.6 mmol) was dissolved in 20 mL of CH₂C1₂ at 0 °C, and l,8-diazabicyclo[5.4.0]undec-7-ene (2.4 mL, 16.4 mmol) was added. The mixture was stirred at 0 °C for 20 min producing an orange solution. A solution ofthe aldehyde product from EX-A-3 (4.04 g, 11.7 mmol) was then added at 0 °C, and the resulting brown mixture was stirred overnight at room temperature, at which time LCMS indicated that no starting material remained. The solvent was removed, and the residue was partitioned between water (60 mL) and ethyl acetate (120 mL). The organic layer was collected, and the aqueous layer was extracted with ethyl acetate (2 x 50 mL). The combined organic layers were washed with water (60 mL) and 10 % aqueous KHSO₄ (60 mL), dried over MgSO₄, filtered and concentrated. The crude material, 5.7 g of an orange oil, was purified by flash column chromatography on silica gel eluting with 10% ethyl acetate in hexane to give 3.5 g (69%) ofthe desired fluoro olefin product as a clear oil. 1H NMR and ¹⁹F NMR indicated that the isolated product had an Z/E ratio of 70:30. HRMS calcd. for C₂₀H₃₂θ₈FN: 456.2010 [M+Naf, found 456.2017. 1H NMR (CDC1₃) ? 1.48 (s, 18H), 2.0 (m, IH), 2.25 (m, IH), 2.6 (m, 2H), 3.7 (s, 3H), 4.25 (m, 2H), 4.9 (m, IH), 5.9 (dt, vinyl, IH, J= 21.2 Hz), 6.1 (dt, vinyl, IH, J= 32.4 Hz). ¹⁹F NMR (CDC1₃) ?: -129.4 (d, 0.7F, J= 34 Hz, 70% Z isomer), -121.6 (d, 0.3F, J= 22 Hz, 30% E isomer).

EX-C-2) The ester product from EX-C-1 (3.5 g, 8.1 mmol) was dissolved in 80 mL of methanol at room temperature, solid NaBH₄ (3 g, 80 mmol) was then added in portions. The mixture was stirred at room temperature for 18 h, at which time HPLC analysis indicated that the reaction was >90 % complete. The reaction was quenched with sat NH₄C1. The product was extracted with ethyl acetate and dried over Na₂SO₄. The organic layer was evaporated to give 3.2 g of crude product as a colorless oil, which was purified by Biotage flash column chromatography eluting with 20% -30% ethyl acetate in hexane to give 2.11 g (67%) of a Z/E mixture ofthe fluoro olefin product as a clear oil along with 0.41 g (13%) ofthe desired pure (Z:E = 97:3 by ¹⁹F NMR) Z-isomer product as a clear oil. HRMS calcd. for C₁₈H₃₀NO₇F: 414.1904 [M+Naf, found 414.1911. 1H NMR (CDC1₃) ? 1.48 (s, 18H), 2.0 (m, IH), 2.2 (m, 3H), 3.7 (s, 3H), 4.1 (dd, 2H, J= 17Hz), 4.8 (dt, IH, J= 39 Hz), 4.9 (m, IH). ¹⁹F NMR

(CDC1₃) ? -119.1 (dt, IF, J= 39 Hz, J- 17 Hz).

EX-C-3) The Z-alcohol product from EX-C-2 (390 mg, 1 mmol) and 3-methyl-l,2,4- oxadiazolin-5-one (130 mg, 1.3 mmol) were dissolved in 20 mL of THF. Then polymer supported-PPh₃ was added into the solution, and the mixture was gently stirred for 10 min. Then diethyl azodicarboxylate was added dropwise, and the mixture was stirred for 1 h at room temperature, at which time LCMS analysis indicated product formation and that no starting material was present. The polymer was filtered off through a celite pad, and the pad was washed with THF. The filtrate was evaporated to give 1.0 g of crude product which was purified by Biotage flash column chromatography eluting with 20 % to 30% ethyl acetate in hexane to give 500 mg of product, contaminated with some hydrazide by-product. This material was further purified by Biotage flash column chromatography eluting with 98:2:0.01 of methylene chloride:methanol:ammon-ium hydroxide to give 180 mg (38%) ofthe desired protected amidine product as a clear oil, that contained only the desired Z-isomer by ¹⁹F NMR. HRMS calcd. for C₂ιH₃₂N₃O₈F: 491.2517 [M+NE₄f , found 491.2523. 1H NMR (CDC1₃) ? 1.5 (s, 18H), 1.9 (m, IH), 2.1 (m, 3H), 2.3 (s, 3H), 3.7 (s, 3H), 4.2 (d, 2H), 4.8 (m, IH), 5.0 (dt, IH, J= 36 Hz). ¹⁹F NMR (CDC1₃) ? -116.5 (dt, IF, J= 38 Hz).

EX-C-4) The product from EX-C-3 (88 mg, 0.19 mmol) was dissolved in 4 mL of 25% acetic acid in water containing a few drops of methanol, and then Zn dust (109 mg, 1.67 mmol) was added. The mixture was agitated under sonication for 3 h. The Zn was filtered off through a celite pad, and the pad was washed with water. The filtrate was evaporated to dryness to give crude product which was purified by reverse-phase HPLC column chromatography on a YMC Combiprep column eluting over 8 min with a gradient of 20-80% A (A: 100% ACN with 0.01% TFA, B: 100% H₂O with 0.01% TFA). The desired product was collected in two fractions, and the combined fractions were concentrated. The product was obtained as a colorless oil as a mixture of trifluoroacetate salts that contained only the desired Z-isomer by ¹⁹F NMR: 30% was mono Boc-protected product: HRMS calcd. for C₁₅H₂₆N₃O₄F: 332.1986 [M+Hf , found 332.2001, and 70% was di-Boc-protected product: HRMS calcd. for C₂₀H₃₄N₃O₆F: 432.2510 [M+Hf, found 432.2503. 1H NMR ofthe di-Boc product (D₂O) ? 1.3 (s, 18H), 1.8 (m, IH), 2.1 (m, 3H), 2.1 (s, 3H), 3.6 (s, 3H), 3.9 (d, 2H), 4.9 (dt, vinyl, IH, J= 37 Hz). ¹⁹F NMR (D₂O) ? -117.3 (dt, IF, J= 37 Hz).

Example C) The combined mono- and di-BOC products from EX-C-4 were dissolved in 30 mL of 6N HCl, and the solution was refluxed for 4 h, at which time LCMS analysis indicated complete reaction. The excess HCl and water was removed in vacuo. Upon completion, 9 mg (40% combined yield for two steps) ofthe desired (2S,5Z)-2-amino-6-fluoro-7-[(l- iminoethyl)amino]-5-heptenoic acid, dihydrochloride product was obtained as a light yellow, very hygroscopic foam, that contained only the desired Z-isomer by ¹⁹F NMR. HRMS calcd. for C₉H₁₆N₃O₂F: 218.1305 [M+Hf, found 218.1320. 1H NMR (D₂O) ? 1.3 (s, 18H), 1.9 (m, 2H), 2.1 (m, 2H), 2.1 (s, 3H), 3.8 (t, IH), 3.9 (d, 2H), 4.9 (dt, vinyl, IH, J= 37Hz). ¹⁹F NMR (D₂O) ? -117.3 (dt, IF, J= 37 Hz).

Example D

(2S,5Z)-2-amino-6-fluoro-7-[(l-iminoethyl)amino]-5-heptenoic acid, trihydrochloride, dihydrate

N(Boc)₂

EX-D-1) The product from EX-D-2 (3.75 g, 10 mmol) was dissolved in 60 mL of methanol, and solid NaBH₄ (4 g, 106 mmol) was added in portions at room temperature over 10 h, at which time HPLC analysis indicated approximately 84% reduction. The reaction mixture was quenched with sat. NH₄C1, and was then extracted with ethyl acetate three times. The combined organic layers were dried over MgSO₄, filtered, and evaporated to give 3.2 g of crude product as a yellow oil. HRMS calcd. for C₁₆H₂₉NO₇: 348.2022 [M+Hf, found: 348.2034. 1H NMR (CD₃OD) ? 4.9 (q, IH), 3.7 (s, 3H ), 3.5 (t, 2H), 3.2 (m, IH), 2.1 (m, ' lH), 1.9 (m, 2H), 1.5 (s, 18H).

EX-D-2) The alcohol product from EX-D-1 (3.2 g, 9.0 mmol) was dissolved in 100 mL of THF and cooled in an ice bath. Carbon tetrabromide (4.27 g, 12.9 mmol) was added, and the resulting solution was stirred at O °C for 30 min under nitrogen. Polymer-supported PPh₃ was added, and the mixture was gently stirred at O °C for 1 h and then overnight at room temperature. The polymer was removed by filtration through celite, and the celite pad was washed with THF. The filtrate was evaporated to give crude product, which was purified by Biotage flash column chromatography eluting with 1:3 ethyl acetate in hexane to give 2.0 g (54%, combined yield over 2 steps) ofthe desired bromo product as a colorless oil. HRMS calcd. for C₁₆H₂₈NO₆Br: 410.1178 [M+Hf, found: 410.1137. 1H NMR (CDC1₃) ? 4.9 (q, IH), 3.7 (s, 3H ), 3.4 (m, 2H), 2.2 (m, 2H), 1.9 (m, 2H), 1.5 (s, 18H).

EX-D-3) A solution of NaOEt (21% in EtOH, 41.1 mL, 0.11 mol) in 60 mL of ethanol was treated with p-methoxy benzenethiol (14.0 g, 0.1 mol), followed by ethyl chlorofluoroacetate (18.3 g, 0.13 mol). The mixture was stirred at room temperature for 2 h and diluted with 250 mL of 1 : 1 hexane in ethyl acetate. The organic layer was washed with water three times, and dried over Na₂SO₄. The dried organic layer was evaporated to give 25 g of crude product which was carried forward without further purification. LCMS for CπH₁₃O₃SF: m/z = 267.10 [M+Naf. 1H NMR (CDCI₃) ? 7.5 (d, 2H), 6.9 (d, 2H), 6.0 (d, IH, J= 51.9 Hz), 4.2 (q, 2H), 3.8 (s, 3H ), 1.2 (t, 3H). ¹⁹F NMR (CDCI₃) ? -146.2 (d, IF, J= 53.6 Hz ).

EX-D-4) A solution ofthe crude product from EX-D-3 (24 g, 0.1 mol) in 200 mL of methylene chloride was cooled to -78 °C and treated with 3-chloroperbenzoic acid (27 g, 0.12 mol) in 200 mL of methylene chloride. The reaction mixture was slowly warmed to room temperature and stirred overnight, at which time LCMS analysis indicated product formation and that no starting material remained. The solid was filtered off, and the filtrate was washed with sat. NaHCO₃ and NH₄C1. The organic layer was dried over MgSO₄ and evaporated to give 30 g of an orange oil, which was purified by Biotage flash column chromatography eluting with 2:1 hexane in ethyl acetate to give 17.5 g (70%) ofthe desired sulfoxide product as an off-white oil. HRMS calcd. for C_πH₁₃O₄FS: 261.0597 [M+Hf, found: 261.0598. 1H NMR (CDC1₃) ? 7.6 (m, 2H), 7.0 (m, 2H), 5.6 (d, IH, J= 50 Hz major diastereomer), 5.4 (d, IH, J= 49 Hz minor diastereomer), 4.2 (q, 2H), 3.8 (s, 3H ), 1.2 (t, 3H). ¹⁹F NMR (CDC1₃) ? -194.3 (d, IF, J= 53.6 Hz major diastereomer), -191.7 (d, IF, J= 50.4 Hz minor diastereomer).

EX-D-5) A suspension of NaH (60% in mineral oil, 212 mg, 5.3 mmol) in 6 mL of dried DMF was cooled to 0 °C under nitrogen and treated with a solution ofthe sulfoxide product from EX-D-4 (1.25 g, 4.8 mmol) in 2 mL of DMF. After stirring at room temperature for 20 min, the mixture was cooled to 5 °C, and the bromo product from EX-D-2 (2.17 g, 5.3 mmol) was added in one portion. The reaction was stirred at room temperature for 3 h, then heated at reflux at 95 °C for 1 h, at which time LCMS analysis indicated product formation. The mixture was poured into an ice/aqueous NH₄C1 mixture. The product was extracted with 1 : 1 hexane in ethyl acetate. The organic layer was dried over Na₂SO₄ and evaporated to give 3.17 g of a crude yellow oil, which was purified by Biotage flash column chromatography eluting with 10% ethyl acetate in hexane to give 1.05 g (50%) ofthe desired fluoro olefin ester product as a colorless oil. ¹⁹F NMR indicated that the isolated product contained 95:5 the desired Z-isomer. HRMS calcd. for C₂₀H₃₂O₈FN: 456.2010 [M+Naf , found: 456.2017. 1H NMR (CDC1₃) ? 1.5 (s, 18H), 2.0 (m, IH), 2.3 (m, 4H), 3.7 (s, 3H), 4.3 (m, 2H ), 4.9 (m, IH), 6.1 (dt, vinyl, IH, J= 32.4 Hz, Z isomer). ¹⁹F NMR (CDC1₃) ? -129.4 (d, 0.95F, J= 34.8 Hz, 95% Z isomer), -121.6 (d, 0.05F, J= 21.6 Hz, 5% E isomer).

EX-D-6) The ester product from EX-D-5 (1.05 g, 2.4 mmol) was dissolved in methanol at room temperature, and solid NaBH₄ was added in portions. The mixture was stirred at room temperature for 18 h, then 2 mL of water was added, and the mixture was stirred for an additional 3 h, at which time HPLC analysis indicated the reaction was >95 % complete. The reaction was quenched with sat NH₄C1. The product was extracted with ethyl acetate, and the organic layer was dried over Na₂SO₄ and evaporated to give 0.95 g of crude product as colorless oil. ¹⁹F NMR indicated that the isolated crude product contained only the desired Z-isomer. HRMS calcd. for Cι₈H₃₀NO₇F: 414.1904 [M+Naf, found: 414.1949. 1H NMR (CDC1₃) ? 1.48 (s, 18H), 2.0 (m, IH), 2.2 (m, 3H), 3.7 (s, 3H), 4.1 (dd, 2H, J= 17 Hz), 4.8 (dt, IH, 7= 36 Hz), 4.9 (m, IH). ¹⁹F NMR (CDC1₃) ? -119.1 (dt, IF, J= 38 Hz, J= 17 Hz).

EX-D-7) The alcohol product from EX-D-6 (0.95 g, 2.4 mmol) and 3-methyl- 1,2,4- oxadiazolin-5-one (290 mg, 2.9 mmol) were dissolved in 60 mL of THF. Polymer-bound triphenyl phosphine was added, and the mixture was gently stirred for 10 min. Then dimethyl azodicarboxylate was added dropwise, and the mixture was stirred for 1 h at room temperature, at which time LCMS analysis indicated product formation and that no starting material remained. The polymer was filtered off through a celite pad, and the pad was washed with THF. The filtrate was evaporated to give a residue which was partitioned between methylene chloride and water. The organic layer was washed with water twice, dried over MgSO₄, and evaporated to give 1.3 g of crude product which was purified by Biotage flash column chromatography eluting with 20 % to 30% ethyl acetate in hexane to give 390 mg (34%, combined yield over 2 steps) ofthe desired protected amidine product as a colorless oil. ¹⁹F NMR indicated that the isolated product contained only the desired Z- isomer. HRMS calcd. for C₂₁H₃₂N₃O₈F: 491.2517 [M+NH₄f , found: 491.2523. 1H NMR (CDC1₃) ? 1.5 (s, 18H), 1.9 (m, IH), 2.1 (m, 3H), 2.3 (s, 3H), 3.7 (s, 3H), 4.2 (d, 2H), 4.8 (m, IH), 5.0 (dt, lH, J= 36 Hz). ¹⁹F NMR (CDCI₃) ? -116.5 (dt,lF, J= 38Hz).

EX-D-8) The product from EX-D-7 (390 mg, 0.82 mmol) was dissolved in 20 mL of 25%

HO Ac in water containing 4 mL of methanol, and Zn dust (482 mg, 7.42 mmol) was added in two portions. The mixture was agitated xmder sonication for 3 h. The Zn was filtered off through a celite pad, and the pad was washed with water. The filtrate was evaporated to dryness to give crude product which was purified by reverse-phase-HPLC. Fractions containing the desired products were collected, combined and concentrated. The products were obtained as colorless oils as a mixture of trifluoroacetate salts, that contained only the desired Z-isomer by ¹⁹F NMR: 30% was mono-Boc protected product: HRMS calcd. for C₁₅H₂₆N₃O₄F: 332.1986 [M+Hf, found 332.2001; 70% was diBoc protected product: HRMS calcd. for C₂₀H₃₄N₃O₆F: 432.2510 [M+Hf, 432.2503. 1H NMR of diBoc product (D₂O) ? 1.3 (s, 18H), 1.8 (m, IH), 2.1 (m, 3H), 2.1 (s, 3H), 3.6 (s, 3H), 3.9 (d, 2H), 4.9 (dt, vinyl, IH, J= 37Hz). ¹⁹F NMR (D₂O) ? -117.3 (dt, IF, J= 37 Hz). Example D) The mono and diBOC products from EX-D-8 were dissolved in 80 mL of 6N HCl and the solution was heated at reflux for 1 hour, at which time LCMS analysis indicated complete reaction. The excess HCl and water was removed in vacuo to give 150 mg (50% combined yield over 2 steps) ofthe desired (2S,5Z)-2-amino-6-fluoro-7-[(l- iminoethyl)amino]-5-heptenoic acid, trihydrochlori.de, dihydrate product as a light yellow very hygroscopic foam. HRMS calcd. for C₉H₁₆N₃O₂F: 218.1305 [M+Hf, found 218.1290. 1H NMR (D₂O) ? 1.3 (s, 18H), 1.9 (m, 2H), 2.1 (m, 2H), 2.1 (s, 3H), 3.8 (t, IH), 3.9 (d, 2H), 4.9 (dt, vinyl, IH, J= 37 Hz). ¹⁹F NMR (D₂O) ?? -117.3 (dt, IF, J= 37 Hz). Anal. Calcd. for C₉H₁₆N₃O₂F»3HCl -2^0: C, 29.81; H, 6.39; N, 11.59; found C, 29.80; H, 6.11; N, 11.20.

Example E

(2R,5E)-2-amino-6-fluoro-7-[(l-iminoethyl)amino]-5-heptenoic acid, dihydrochloride, monohydrate

EX-E-1) Trimethylsilyl chloride is added dropwise to a cooled solution of D-glutamic acid in methanol at 0 °C. The resulting clear, colorless solution is allowed to stir at room temperature until analysis by thin layer chromatography shows that no starting material remains. The reaction is then cooled to 0 °C, triethylamine is added, and a white precipitate forms. Di-tert-butyldicarbonate is added, and the mixture is allowed to warm to room temperature. After 3 h the solvent is removed, and diethyl ether is added. The solution is filtered, and the filter cake is rinsed with additional diethyl ether. The filtrate is concentrated to give the desired mono-Boc diester product which is carried onto the next step without further purification.

EX-E-2) To a solution ofthe crude product from EX-E-1 in acetonitrile at room temperature is added 4-dimethylaminopyridine and di-tert-butyldicarbonate. The resulting mixture is stirred at room temperature, until analysis by thin layer chromatography shows that most of the starting material is consumed. The solvent is removed in vacuo, and the resulting residue is purified by flash column chromatography on silica gel to give the desired di-Boc protected diester product.

EX-E-3) A solution of DIBAL is added dropwise to a cold solution of EX-E-2 in anhydrous diethyl ether at -78 °C. After 30 min at -78 °C, the solution is quenched with water and allowed to warm to room temperature. The resulting cloudy mixture is diluted with ethyl acetate, dried over MgSO₄ and filtered through a pad of celite. The filtrate is concentrated, and the resulting residue is purified by flash column chromatography on silica gel to give the desired aldehyde product

EX-E-4) To a cold (-78 °C) solution of triethyl 2-fluorophosphonoacetate in THF is added n- butyl lithium. This mixture is stirred at -78 °C producing a bright yellow solution. A solution ofthe product from EX-E-3 in THF is then added via syringe, and the resulting mixture is stirred at -78 °C, until analysis by thin layer chromatography shows that no starting material remains. The reaction is quenched at -78 °C with sat. aqueous NH₄C1. The organic layer is collected, and the aqueous layer is extracted with diethyl ether. The combined organics are washed with water and brine, dried over MgSO₄, filtered and concentrated. The crude material is then purified by flash column chromatography on silica gel to give the desired fluoro olefin product.

EX-E-5) To a solution of EX-E-4 in methanol at room temperature is added solid NaBH₄ in portions. The reaction is stirred at ambient temperature until analysis by thin layer chromatography shows that most ofthe starting material is consumed. The reaction is quenched with sat. aqueous NH₄C1 and extracted with ethyl acetate. The organic layers are combined, dried over MgSO , filtered and concentrated. The crude material is purified by flash column chromatography on silica gel to give the desired allylic alcohol product.

EX-E-6) To a mixture of EX-E-5, polymer-supported triphenylphosphine and 3-methyl- l,2,4-oxadiazolin-5-one in THF is added dropwise dimethylazodicarboxylate. The reaction mixture is stirred at room temperature until analysis by thin layer chromatography shows that no starting material remains. The mixture is filtered through celite, and the filtrate is concentrated. The resulting yellow oil is partitioned between methylene chloride and water. The organic layer is¹ separated, washed with water and brine, dried over MgSO₄, filtered and concentrated. The crude material is purified by flash column chromatography on silica gel to give the desired protected E-allylic amidine product.

EX-E-7) The product from EX-E-6 is dissolved in methanol and acetic acid in water. Zinc dust is added, and the mixture is agitated under sonication until HPLC analysis shows that little ofthe starting material remains. The Zn dust is filtered through celite from the reaction mixture, and the filtrate is concentrated. The crude material is purified by reverse-phase HPLC column chromatography. Fractions containing product are combined and concentrated affording the desired acetamidine product as a trifluoroacetate salt.

Example E) A solution of EX-E-7 in 6.0 N HCl is refluxed for 1 h. The solvent is removed in vacuo. The resulting solid is dissolved in water and concentrated repeatedly from 1.0 N HCl to remove any remaining TFA salts to give the desired (2R,5E)-2-amino-6-fluoro-7-[(l- iminoethyl)amino]-5-heptenoic acid, dihydrochloride product. Example F

EX-F-1) To a THF (45ml) solution ofthe product of EX-A-3 (5.0g, 11.5mmol) under nitrogen was added dropwise a solution of Red-Al (5.22ml, 17.4mmol) in 5.6 mL THF over 30 minutes. The internal temperature was kept below -10 °C. After 5 minutes, the reaction was quenched with 33.7ml of 1.3M Na«K tartrate. Toluene (11 mL) was added to the mixture to improve separation. The organic layer was washed with 33.7ml of 1.3M Na*K tartrate followed by brine (40 mL). The organic layers were combined, dried over MgSO4, filtered and concentrated. The crude material, 3.8 g (84%) of light yellow oil, was carried on directly into the next step. LCMS: m/z = 414.2 [M+Naf. ^!H NMR (CDC1₃) ? 1.48 (s, 18H), 1.95 (m, IH), 2.1 (m, IH), 2.2 (m, IH), 2.35 (t, IH), 3.7 (s, 3H), 4.25 (m, 2H), 4.8 (m, IH), 5.15 (dt, IH, J= 20 Hz). ¹⁹F NMR (CDC1₃) ? -119.1 (d, 0.02F, J= 37 Hz, 2% Z- isomer), -111.8 (d, 0.98F, J= 24 Hz, 98% E-isomer).

EX-F-2) To a solution ofthe product of EX-F-1 (50.0 g, 0.128 mol) in 500 mL of methylene chloride at -10 °C was added triethylamine (18.0 g, 0.179 mol). A solution of methanesulfonyl chloride (17.5 g, 0.153 mol) in 50 mL methylene chloride was added slowly to maintain temperature at -10 °C. The reaction was stirred for 45 min at -10 °C, at which time analysis by thin layer chromatography (50% ethyl acetate in hexane) and LCMS showed that most ofthe starting material was consumed. The reaction was quenched with 600 mL of 1.0 M citric acid and extracted with ethyl acetate (2 x 400 mL). The organic layers were combined, dried over MgSO₄, filtered and concentrated. The crude material, 70 g of yellow oil, was carried directly into the next step. LCMS: m/z = 492.2 [M+Na].

EX-F-3) To a solution ofthe product of EX-F-2 (70.0 g, 0.128 mol) in 400 mL of dimethyl formamide at room temperature was added potassium 3-methyl-l,2,4-oxadiazolin-5-onate (28.7 g, 0.192 mol). The reaction was stirred for 2.5 h at room temperature, at which time analysis by thin layer chromatography (30% ethyl acetate in hexane) and LCMS showed that the starting material was consumed. The reaction was diluted with 400 mL of water and extracted with ethyl acetate (5 x 400 L). The organic layers were combined, washed with 400 mL water, 400 mL brine, dried over MgSO₄, filtered and concentrated. The crude material, 70 g of yellow oil, was purified by flash column chromatography on silica gel eluting with 1:4 ethyl acetate in hexane to give 38 g (63%) of a slightly yellow oil.

EX-F-4) A combination of product of several duplicate preparations of EX-F-3 was purified by HPLC column chromatography on Merk silica gel MODCOL column at a flow of 500 mL/min isocratic at 60:40 MtBE:heptane. A second purification on the 63 g recovered was a chiral HPLC column chromatography on a Chiral Pak-AD column running at a flow of 550 mL/min isocratic at 10:90 A:B (A: 100% ethanol, B: 100% heptane). Fractions containing product were combined and concentrated affording 41 g (68%) ofthe desired protected L,E- allylic amidine product as a clear oil, that contained only the desired L and E-isomer by ¹⁹F NMR and chiral chromatography. LCMS: m/z = 496.2 [M+Naf. [M+NH₄f . HRMS calcd. for C₂₁H₃₂FN₃O₈: 491.2507 [M+ NH₄f, found: 491.2517. 1H NMR (CDC1₃) ? 1.48 (s, 18H), 1.85 (m, IH), 2.2 (m, 3H), 2.25 (s, 3H), 3.64 (s, 3H), 4.25 (m, 2H), 4.8 (m, IH), 5.3 (dt, IH, J= 20 Hz). ¹⁹F NMR (CDC1₃) ? -110.8 (q, IF, J= 20 Hz).

EX-F-5) The product from EX-F-4 (22.5 g, 0.047 mol) was dissolved in 112 mL of methanol. Vigorous stirring was begun and 225 mL of 40% acetic acid in water followed by zinc dust (11.5 g, 0.177 mmol) was added. The stirring reaction was placed under reflux (approx. 60 °C) for 2.5 h, at which time HPLC analysis showed that most ofthe starting material had been consumed. The reaction was cooled and the Zn was filtered from the reaction mixture through celite, washing the celite well with additional methanol. The filtrate and methanol washings were combined and concentrated. The resulting oily-white solid was washed with methylene chloride (2 x 500 mL) and filtered through a celite pad, an additional 500 mL methylene chloride wash was performed. The filtrates were combined and concentrated to provide a light yellow oil. The crude material, 39 g of a light-yellow oil, was purified by plug filtration on 200 mL silica gel eluting with 80:19:1 methanol: methylene chloride: acetic acid to give 13 g (83%) ofthe desired product. LCMS: m/z = 432.3 [M+H]⁺. 1 [M+Hf. HRMS calcd. for C₁₅H₂₆FN₃O₄: 332.1986 [M+H]⁺, found: 332.1982. 1H NMR (CD₃OD) ? 1.42 (s, 9H), 1.7 (m, IH), 1.9 (m, IH), 2.17 (m, 2H), 2.22 (s, 3H), 3.3 (m, IH), 3.7 (s, 3H), 4.2 (d, 2H), 5.1 (dt, vinyl, IH, J= 21 Hz). ¹⁹F NMR (CD₃OD) ? -110.83 (m, IF, J= 21 Hz).

Example F) A solution ofthe product of EX-F-5 (22 g, 0.066 mol) in 750 mL of 6.0 N HCl was refluxed for 45 min. The solvent was removed in vacuo. The resulting solid was dissolved in water and concentrated three additional times. The crude material was purified by reverse-phase HPLC column chromatography on a YMC ODS-AQ column eluting over 60 min pumping 100% isocratic B for 30 min followed by a gradient of 0-100% A for 10 min and a 100% A wash for 20 min (A: 100% acetonitrile, B: 100% H₂O with 0.0025% acetic acid). Fractions containing product were combined and concentrated affording 3.5 g (68%) of the desired acetamidine product as a dihydorchloride salt, that contained only the desired (2S,5E)-2-amino-6-fluoro-7-[(l-iminoethyl)amino]-5-heptenoic acid, dihydrochloride product was obtained as a white solid, m.p. 51.5-56.3 °C, that contained only the desired Ε- isomer by ¹⁹F NMR. LCMS: m/z = 218.1 [M+H]⁺. HRMS calcd. for C₉H₁₆FN₃O₂: 218.1305 [M+Hf, found: 218.1325. 1H NMR (D₂O) ? 1.8 (m, 2H), 2.05 (m, 2H), 2.1 (s, 3H), 3.7 (t, IH), 4.00 (d, 2H), 5.3 (dt, vinyl, IH, J= 21 Hz). ¹⁹F NMR (D₂O) ? -109.9 (m, IF, J= 20 Hz). [?]₅₈₉ = +15.3 (C, 0.334, (H₂0); ). [?]₃₆₅ = +52.8 (C, 0.334, (H₂0)

Example G

(2S,5E)-2-amino-6-fluoro-7-[(l-hydroximinoethyl)amino]-5-heptenoic acid

EX-G-1) Gaseous HCl was bubbled for 5 min through a stirring cold (0 °C) solution ofthe product of EX-F-3 (14 g, 30.0 mmol) in 100 mL of methanol. The resulting dark yellow solution was stiπed an additional 30 min, at which time HPLC indicated complete consumption of starting material. The resulting mixture was neutralized with saturated NaHCO₃ to pH=8, and the product was extracted out with EtOAc. The organic layer was dried over MgSO₄ and concentrated to give the desired amino ester product as a dark yellow oil that was carried on crude to the next step. LCMS: m/z = 274 [M+Naf. 1H NMR (CDC1₃) ? 1.8 (m, 4H), 2.25 (s, 3H), 3.42 (bm, IH), 3.80 (s, 3H), 4.4 (dd, 2H), 5.40 (dt, vinyl, IH, J= 21 Hz). ¹⁹F NMR (CDC1₃) ? -110.38 (m, IF, J- 21 Hz). Example G) A solution ofthe product of EX-G-1 (8 g, 30 mmol) in 70 mL of 2.5N NaOH was stirred for 10 min, at which time HPLC analysis indicated the complete consumption of starting material. The resulting solution was neutralized with 12N HCl (approximately 50 mL) to pH=7-8 and concentrated. The resulting slurry was washed with methanol, filtered to remove salts and concentrated to a brownish oil. The crude material was purified by reverse- phase HPLC column chromatography on a YMC ODS-AQ column eluting over 60 min pumping 100% isocratic B for 30 min followed by a gradient of 0-100% A for 10 min and a 100% A wash for 20 min (A: 100% acetonitrile, B: 100%). Fractions containing product were combined and concentrated affording 1.0 g (14%) ofthe desired product as a white solid. The product was recrystalhzed from hot water and isopropyl alcohol and collected by filtration to afford pure (2S,5E)-2-amino-6-fluoro-7-[(l-hydroximinoethyl)amino]-5- heptenoic acid as a white crystalline solid. Melting point: 198.00-200.00 °C. LCMS: m/z = 234.1 [M+Hf. 1H NMR (D₂O) ? 1.8 (m, 4H), 2.05 (m, 2H), 3.6 (t, IH), 3.9 (d, 2H), 5.2 (dt, vinyl, IH, J= 21 Hz). ¹⁹F NMR (D₂O) ? -112.1 (m, IF, J= 20 Hz). ). Anal, calcd. for C₉H₁₆FN₃O₃: C, 46.35; H, 6.91; N, 18.02; O, 20.58. Found: C, 46.44; H, 6.95; N, 17.94; O, 20.78. Chiral analysis >97.7%: CrownPak CR(+) at 0.8 mL/min isocratic with 100% A (A: aqueous HClO₄, pH=1.5).

Example H

(2S,5E)-2-amino-6-fluoro-7-[(l-iminoethyI)amino]- N-(lH-tetrazol-5-yl) 5-heptenamide, dihydrochloride

EX-H-1) The product from EX-F-3 (6.1 g, 0.013 mol) was dissolved in 4 mL of methanol. Vigorous stirring was begun and 10 mL of 6N HCl was added. The stirring reaction was placed under reflux (approx. 60 °C) for 18 h, at which time HPLC analysis showed that most ofthe starting material had been consumed. The reaction was cooled and concentrated to 3.3 g (100%) of orange oil. LCMS: m/z = 282 [M+Naf.

EX-H-2) The product from EX-H-1 (3.3 g, 0.013 mol) was dissolved in 12 mL of 1 :1 H₂O:dioxane. Stirring was begun and triethylamine (1.95 g, 0.019 mol) was added. The reaction was cooled to 0 °C and di-tert-butyldicarbonate (3.4 g, 0.016 mol) was added. The reaction was allowed to warm to room temperature at wliich time acetonitrile (4 mL) was added to dissolve solids. The reaction was stirred at room temperature for 18 h at which time HPLC analysis showed that most ofthe starting material had been consumed. The reaction was quenched with 1.0N KHSO₄ (25 mL), extracted with ethyl acetate (3 x 50 mL) and the organic layers dried over MgSO₄ and concentrated. The crude material, 3.5 g of a dark oil, was purified by flash chromatography eluting with 4:95:1 methanol: methylene chloride: acetic acid to give 2.4 g (52%) of desired product as a light-yellow oil. LCMS: m/z = 382

EX-H-3) The product from EX-H-2 (2.4 g, 0.007 mol) was dissolved in 13 mL THF. Stirring was begun and 5-aminotetrazole monohydrate (0.83 g, 0.008 mol) was added followed by 1,3-diisopropylcarbodiimide (1.0 g, 0.008 mol). The resulting mixture was allowed to stir at room temperature for 3 h at which time HPLC showed that most ofthe starting material had been consumed. To the reaction was added 12 mL water and the THF was removed by vaccum distillation. Ethanol (30 mL) was added and the reaction was heated to reflxxx. After 15 min at reflux, the reaction was cooled to -10 °C at which time the desired product precipitated from solution. The product was collected by filtration to afford 1.25 g (50%) of a white solid. LCMS: m/z = 449 [M+Naf.

EX-H-4) The product from EX-H-3 (1.0 g, 0.0023 mol) was dissolved in 5 mL of methanol. Vigorous stirring was begun and 10 mL of 40% acetic acid in water followed by zinc dust (0.5 g, 0.008 mol) was added. The stirring reaction was placed under reflux (approx. 60 °C) for 1.5 h, at which time HPLC analysis showed that most ofthe starting material had been consumed. The reaction was cooled and the Zn was filtered from the reaction mixture through celite, washing the celite well with additional methanol. The filtrate and methanol washings were combined and concentrated. The resulting oily- white solid was purified by reverse-phase HPLC column chromatography on a YMC ODS-AQ column eluting over 60 min pumping 100% isocratic B for 30 min followed by a gradient of 0-100% A for 10 min and a 100% A wash for 20 min (A: 100% acetonitrile, B: 100% H₂O with 0.0025% acetic acid). Fractions containing product were combined and concentrated affording 0.390 g (44%) ofthe desired acetamidine product as a white solid. LCMS: m/z = 407.3 [M+Na].

Example H) The product from EX-H-4 (0.30 g, 0.780 mmol) was dissolved in 5 mL of cone HO Ac. To this was added 1 L of 4N HCl in dioxane. The reaction was stirred 5 min. at room temperature. The solvent was removed in vacuo. The resulting solid was dissolved in water and concentrated three additional times. HPLC indicated amounts of starting material. The solid was dissolved in IN HCl and stirred 3h at which time HPLC indicated that most of the starting material had been consumed. The solution was concentrated affording 290 mg (98%) ofthe desired acetamidine product as a dihydorchloride salt. LCMS: m/z = 285.1 [M+H].

Example I

S-[2-[(l-Iminoethyl)amino]ethyl]-2-methyl-L-cysteine, dihydrochloride

Example-I-1) (2R,4R)-Methyl-2-tert-butyl-l,3-thiazoline-3-formyl-4-carboxylate

See Jeanguenat and Seebach, J. Chem. Soc. Perkin Trans. 1, 2291 (1991) and Pattenden et al. Tetrahedron, 49, 2131 (1993): (R)-cysteine methyl ester hydrochloride (8.58 g, 50 mmol), pivalaldehyde (8.61 g, 100 mmol), and triethylamine (5.57 g, 55mmol) were refluxed in pentane (800 ml) with continuous removal of water using a Dean-Stark trap. The mixture was filtered and evaporated. The resultant thiazolidine (9.15 g, 45 mmol) and sodium formate (3.37 g, 49.5 mmol) were stirred in formic acid (68 ml) and treated with acetic anhydride (13 mL, 138 mmol), dropwise over 1 hour at 0-5 °C. The solution was allowed to warm to RT and stir overnight. The solvents were evaporated and the residue was neutralized with aqueous 5% NaHCO₃ and extracted with ether (3X). The combined organic layers were dried (anhy. MgSO₄), filtered, and evaporated to give the title compound which was crystallized from hexane-ether as white crystals (8.65 g) (80% overall, 8:1 mixture of conformers). 1H NMR (CDC1₃) ??major conformer: 1.04 (s, 9H), 3.29 (d, IH), 3.31 (d, IH), 3.78 (s, 3H), 4.75 (s, IH), 4.90 (t, IH), 8.36 (s, IH). MS m/z (electrospray) 232 (M+H)⁺ (100%), 204 (10) 164 (24).

Example-I-2) (2R,4R)-Methyl-2-tert-butyl-l,3-thiazoline-3-formyl-4-methyl-4-carboxylate To a solution ofthe product of Example-I-1, (2R,4R)-Methyl-2-tert-butyl-l,3-thiazoline- 3-formyl-4-carboxylate (8.65 g, 37.4 mmol), in anhydrous tetrahydrofuran (130 mL) under N₂ at -78 °C was added DMPU (25 mL) and the mixture stirred for 5 min. Lithium bis(trimethylsilyl) amide, 1 M in tetrahydrofuran, (37.5 mL), was added, and the mixture stirred for 30 min. After methyl iodide (5.84 g, 41.1 mmol) was added, the mixture was held at -78 °C for 4 hr and then warmed to room temperature with continuous stirring. The solvents were evaporated in vacuo and brine and ethyl acetate was added. The aqueous phase was extracted 3x EtOAc, and the combined organic layers were washed with 10% KHSO , water, and brine. They were then dried (anhy. MgSO₄), filtered, and stripped of all solvent under reduced pressure. Chromatography ofthe residual oil on silica with 1-10% EtOAc/hexane yielded the title compound (5.78 g, 63%, 2.4:1 mixture of conformers). ^!H NMR (CDC1₃) ??major conformer, 1.08 (s, 9H), 1.77 (s, 3H), 2.72 (d, IH), 3.31 (d, IH), 3.77 (s, 3H), 4.63 (s, IH), 8.27 (s, IH); minor conformer, 0.97 (s, 9H), 1.79 (s, 3H), 2.84 (d, IH), 3.63 (d, IH), 3.81 (s, 3H), 5.29 (s, IH), 8.40 (s, IH); MS m z (electrospray) 246 (M+H)⁺ (100%), 188 (55) 160 (95). Retention time of 16.5 min on a Daicel Chemical Industries Chiracel OAS column, 10-40% IPA hexane 0-25 min, >95% ee. Example-I-3) (2R) 2-Methyl-L-cysteine hydrochloride

The product of Example-I-2, (2R,4R)-Methyl-2-tert-butyl-l,3-thiazoline-3-formyl-4- methyl-4-carboxylate, (5.7 g, 23.2 mmol) was stirred with 6N HCl (lOOmL) under N₂ and held at vigorous reflux for 2 days. The solution was cooled, washed with EtOAc and evaporated to yield the product (2R) 2-methyl-cysteine hydrochloride (3.79 g, 95%) as a light yellow powder. 1H NMR (DMSO-d₆)?? 1.48 (s, 3H,) 2.82 (t, IH), 2.96 (bs, 2H), 8.48 (s, 3H). MS m/z (electrospray) 136 [M+H⁺].

Example-I-4) S-[2- [ [( 1 , 1 -dimethylethoxy)carbonyl] amino] ethyl] -2-methyl-L-cysteine trifluoroacetate

Sodium hydride (2.6 g, 60% in mineral oil, 65 mmol) was added to an oven-dried, vacuum-cooled RB flask, containing oxygen-free l-methyl-2-pyrrolidinone (5 mL). The mixture was cooled to -10 °C and stirred under N₂. The product of Example-I-3, 2-Methyl- L-cysteine hydrochloride, (3.6 g, 21.0 mmol) dissolved in oxygen-free l-methyl-2- pyrrolidinone (25 ml), was added in portions. After all H₂ evolution ceased, 2-[(l,l- dimethylethoxycarbonyl)-amino]ethyl bromide (4.94 g, 21 mmol) in oxygen-free l-methyl-2- pyπolidinone (15 mL) was added at -10 °C. The reaction was then stirred for 4 hr allowing warming to room temperature. The solution was neutralized with 1 N HCl and the 1-methyl- 2-pyrrolidinone was removed by evaporation in vacuo. Reverse-phase chromatography with 1-20% acetonitrile in 0.05% aqueous trifluoro acetic acid solution yielded the title compound (5.9 g), recovered by freeze-drying appropriate fractions. 1H NMR (DMSO-d₆/D₂O) ? 1.31 (s, 9H), 1.39 (s, 3H), 2.55 (m, 2H), 2.78 (d, IH), 3.04 (d, IH), 3.06 (t, 2H). HRMS calc. for C11H₂₂N2O4S: 279.1375 (M+H⁺), found 279.1379.

Example-I-5) S-(2-aminoethyl)-2-methyl-L-cysteine hydrochloride

The product of Example-I-4, S-[2-[[(l,l-dimethylethoxy)carbonyl]amino]ethyl]-2- methyl-L-cysteine trifluoroacetate, (5.5 g, 14.0 mmol) was dissolved in 1 N HCl (100 mL) and stirred at room temperature under nitrogen overnight. The solution was removed by freeze-drying to give the title S-(2-aminoethyl)-2-methyl-L-cysteine hydrochloride, ^!H NMR ?(DMSO-d₆/D₂O) ? 1.43 (s, 3H), 2.72 (m, 2H), 2.85 (d, 1 H), 2.95 (t, 2H), 3.07 (d, IH). m/z [M+H⁺] 179.

Example I) The product of Example-I-5, was dissolved in H₂O, the pH adjusted to 10 with 1 NNaOH, and ethyl acetimidate hydrochloride (1.73 g, 14.0 mmol) was added. The reaction was stirred 15-30 min, the pH was raised to 10, and this process repeated 3 times. The pH was adjusted to 3 with HCl and the solution loaded onto a washed DOWEX 50WX4- 200 column. The column was washed with H O and 0.25 M NH₄OH, followed by 0.5 M NH₄OH. Fractions from the 0.5 M NH₄OH wash were immediately frozen, combined and freeze-dried to give an oil that was dissolved in IN HCl and evaporated to give the title compound as a white solid (2.7 g). 1H NMR (DMSO-d₆/D₂O) ? 1.17 (s, 3H), 2.08 (s, 3H), 2.52 (d, IH), 2.68 (m, 2H), 2.94 (d, IH), 3.23 (t, 2H). HRMS calc. for C₈H₁₈N₃O₂S: 220.1120 [M+H⁺], found 220.1133.

Example J

2HCI

2- [ [ [2- [(1 -Iminoethyl) amino] ethyl] thio] methyl] -0-methy 1-D-serine, dihydrochloride

The procedures and methods utilized in this example were identical to those of Example I except that in step Example-I-2 methoxymethyl iodide was used instead of methyl iodide. These procedures yielded the title product as a white solid (2.7 g). 1H NMR (D₂O) ? 2.06 (s, 3H), 2.70 (m, 3H), 3.05 (d, IH), 3.23 (s, 3H), 3.32 (t, 2H), 3.46 (d, IH), 3.62 (d, IH). HRMS calc. for C₉H₂₀N₃O₃S: 250.1225 [M+Ef], found 250.1228. Example K

S-[(lR)-2-[(l-Iminoethyl)amino]-l-methylethyl]-2-methyl-L-cysteine, dihydrochloride

Example-K-1) (S)-l -[(benzyloxycarbonyl)amino]-2-propanol

To a solution of (S)-l-amino-2-propanol (9.76 g, 130 mmol)in anhydrous benzene (60 mL) at 0 °C was added benzyl chloroformate (10.23 g, 60 mmol) in anhydrous benzene (120 mL) slowly, in portions, over a period of 20 min while vigorously stirring under an atmosphere of nitrogen. The mixture was stirred for 1 hour at 0 °C, then allowed to warm to room temperature and stirred for a further 2 hours. The mixture was washed with water (2X) and brine (2X) before the organic layer was dried over anhydrous MgSO₄. Evaporation of all solvent gave the title product as an oil. 1H NMR (CDC1₃) ? 1.22 (d, 3H,) 2.40 (bs, IH), 3.07 (m, IH), 3.37 (m, IH) ), 3.94 (m, IH), 5.16 (s, 2H), 5.27 (m, IH), 7.38 (m, 5H). MS m/z (electrospray) 232 [M+23]⁺ (100%), 166 (96).

Example-K-2) (S)-l-[(benzyloxycarbonyl)amino]-2-propanol tosylate

To a solution ofthe product of Example-K-1, (S)-l-[(benzyloxycarbonyl)amino]-2- propanol, (9.74 g, 46.7 mmol) and triethylamine 7.27 g, 72 mmol) in methylene chloride (60 mL) at 0°C was added toluene sulfonyl chloride (9.15 g, 48 mmol) in methylene chloride (18 mL) slowly, in portions, over a period of 20 min while vigorously stirring under nitrogen. The mixture allowed to warm to room temperature and stirred for a further 36 hours under nitrogen. The organic layer was washed with IN HCl, water, 5% NaHCO₃ solution, water and brine before it was dried over anhydrous MgSO₄. Evaporation of all solvent gave a white solid which was passed though a silica plug with ethyl acetate/hexane (1 :4) to remove excess toluene sulfonyl chloride and then with ethyl acetate/hexane (1:3) to give the title product as white crystals. This material was recrystalhzed from ethyl acetate/hexane to give white needles (10.8 g). 1H NMR (CDC1₃) ??1.22 (d, 3H,) 2.39 (s, 3H), 3.20 (m, IH), 3.43 (dd, IH) ), 4.66 (m, IH), 5.02 (m, IH), 5.04 (ABq, 2H), 7.34 (m, 7H), 7.77 (d, 2H). MS m z (electrospray) 386 [M+23]⁺ (100%), 320 (66). The product was examined on a Regis Technologies Inc. Perkle Covalent (R,R) 7-GEM1 HPLC column using mobile phase of isopropanol/hexane and a gradient of 10% isopropanol for 5 min, then 10 to 40% isopropanol over a period of 25 min, and using both UV and Laser Polarimetry detectors. Retention time major peak: 22.2 min, >98 % ee.

Example-K-3) S-[(lR)-2-(Benzyloxycarbonylamino)-l-methylethyl]-2-methyl-L-cysteine trifluoroacetate

The product of Example-I-3, 2-methyl-L-cysteine hydrochloride, (1 g, 6.5 mmol) was added to an oven dried, N₂ flushed RB flask, dissolved in oxygen-free l-methyl-2- pyrrolidinone (5 mL), and the system was cooled to 0 °C. Sodium hydride (0.86 g, 60% in mineral oil, 20.1 mmol) was added and the mixture was stiπed at 0 °C for 15 min. A solution ofthe product of Example-K-2, (2S)-l-[(N-benzyloxycarbonyl)amino]-2-propanol tosylate (2.5 g, 7 mmol) dissolved in oxygen-free l-methyl-2-pyrrolidinone (10 mL) was added over 10 min. After 15 min at 0 °C, the reaction mixture was stirred at room temperature for 4.5 hours. The solution was then acidified to pH 4 with IN HCl and l-methyl-2-pyrrolidinone was removed by evaporation in vacuo. Reverse phase chromatography with 20-40 % acetonitrile in 0.05% aqueous trifluoro acetic acid solution yielded the title compound in (0.57g), recovered by freeze-drying. 1H NMR (H₂O, 400 MHz) ? 1.0 (d, 3H), 1.4 (s, 3H), 2.6 (m, 2H), 2.8 (m, IH), 3.1 (m, 2H), 3.6 (s, IH), 5.0 (ABq, 2H), 7.3 (m, 5H). MS m z (electrospray): 327 [M+H⁺] (100%), 238 (20), 224 (10), and 100 (25).

Example-K-4) S-[(lR)-2-Amino-l-methylethyl]-2-methyl-L-cysteine hydrochloride

The product of Example-K-3, S-[(lR)-2-(Benzyloxycarbonylamino)-l-methylethyl]-2- methyl-L-cysteine trifluoroacetate, (0.5 g, 1.14 mmol) was dissolved in 6N HCl and refluxed for 1.5 hour. The mixture was then cooled to room temperature and extracted with EtOAc. The aqueous layer was concentrated in vacuo to give the title product, (2R, 5R)-S- (1 -amino- 2-propyl)-2-methyl-cysteine hydrochloride (0.29 g), which was used without further purification. 1H NMR (H₂O, 400 MHz) ? 1.2 (m, 3H), 1.4 (m, 3H), 2.7 (m, IH), 2.8-3.2 (m, 2H), 3.4 (m, IH). (some doubling of peaks due to rotameric forms). MS m/z (electrospray): 193 [M+ϊT] (61%), 176 (53), 142 (34), 134 (100), and 102 (10).

Example K) The product of Example-K-4, S-[(lR)-2-Amino-l-methylethyl]-2-methyl-L- cysteine hydrochloride, (0.2 g, 0.76 mmol) was dissolved in 2 mL of H₂O, the pH was adjusted to 10.0 with IN NaOH, and ethyl acetimidate hydrochloride (0.38 g, 3 mmol) was added in four portions over 10 minutes, adjusting the pH to 10.0 with IN NaOH as necessary. After lh, the pH was adjusted to 3 with IN HCl. The solution was loaded onto a water- washed DOWEX 50WX4-200 column. The column was washed with H₂O and 0.5N NH₄OH. The basic fractions were pooled and concenfrated to dryness in vacuo. The residue was acidified with IN HCl and concentrated to the Example K title product, (49 mg). 1H NMR (H₂O, 400 MHz) ? 1.3-1.0 (m, 3H), 1.5 (m, 3H), 2.1-1.8 (m, 3H), 3.4-2.6 (m, 5H), 3.6 (m, IH) (rotamers observed). MS m z (electrospray): 234 [M+H⁺] (100%), 176 (10), and 134 (10).

Example L

S-[(lS)-2-[(l-Iminoethyl)amino]-l-methylethyl]-2-methyl-L-cysteine, dihydrochloride

The procedures and methods employed here were identical to those of Example K, except that in step Example-K-1 (R)-l-amino-2-propanol was used instead of (S)-l-amino-2- propanol to give the title material, S-[(lS)-2-[(l-hninoethyl)amino]-l-methylethyl]-2-methyl- L-cysteine hydrochloride. 1H NMR (H₂0, 400 MHz) ? 3.6 (m, IH), 3.4-2.6 (m, 5H), 2.1-1.8 (m, 3H), 1.5 (m, 3H), and 1.3-1.0 (m, 3H). HRMS calc for C₉H₁₉N₃O₂S [M+H⁺]: 234.1276. Found: 234.1286.

Example M

S-[2-[(l-Iminoethyl)amino]ethyl]-2-ethyl-L-cysteine, dihydrochloride

The procedures and methods used in this synthesis were the same as those used in Example I except that ethyl triflate was used in Example-I-2 instead of methyl iodide. Reverse phase chromatography, using a gradient of 10-40% acetonitrile in water, was used to purify the title product (20% yield). 1H NMR (D₂O)?? 0.83 (t, 3H), 1.80 (m, 2H), 2.08 (s, 3H), 2.68 (m, IH), 2.78 (m, IH), 2.83 (m, IH), 3.11 (m, IH), 3.36 (t, 2H). HRMS calc. for C₉H₂₀N₃O₂S: 234.1276 [M+H⁺], found 234.1284.

Example N

2- [ [ [ [2-(l -Iminoethyl)amino] ethyl] thio] methyl] -D-valine, dihydrochloride

Example-N-1) Isopropyl triflate

Silver triflate (25.25 g, 98.3 mmol) stirred in diethyl ether (300 mL) under nitrogen was treated with isopropyl iodide (16.54 g, 98.5 mmol) in ether (200 mL) over 15 minutes. The mixture was stirred for 10 minutes and then filtered. The filtrate was distilled at reduced pressure. The distillate was redistilled at atmospheric pressure to remove the majority of the diethyl ether, leaving a mixture of the title isopropyl triflate-diethyl ether (84:16 by weight) (15.64 g, 70% corrected) as a colorless liquid. 1H NMR (CDC1₃, 400 MHz) ? 1.52 (d, 6H), 5.21 (septet, IH).

The procedures and methods utilized here were the same as those used in Example I except that isopropyl triflate replaced methyl iodide in Example-I-2. The crude title product was purified by reversed phase chromatography using a gradient elution of 10-40% acetonitrile in water. 1H NMR (H₂O, 400 MHz) ?? 0.94 (dd, 6H), 2.04 (septet, IH), 2.10 (s, 3H), 2.65, 2.80 (d m, 2H), 2.85, 3.10 (dd, 2H), 3.37 (t, 2H). HRMS calc. for C₁₀H₂₂N₃O₂S: 248.1433 [M+H⁺], found 248.1450. Example O

2TFA S-[2-(l-Iminoethylamino)ethyl]-2-methyl-(D/L)-cysteine, bistrifluoroacetate

Example-O-1) S-(2-aminoethyl)-L-cysteine, methyl ester

A 10 g (50 mmol) sample of S-(2-aminoethyl)-L-cysteine was dissolved in 400 mL of methanol. Into this cooled solution was bubbled in anhydrous HCl for 30 minutes. After stirring at room temperature overnight, the solution was concentrated to afford 12.7 g ofthe title compound.

ExampIe-O-2) N- {4-chlorophenyl)methylene]-S-[2-[[(4- chlorophenyl)methylene]amino]ethyl]-L-cysteine, methyl ester

A 12.7 g (50 mmol) sample ofthe product of Example-O-1, S-(2-aminoethyl)-L-cysteine methyl ester, was dissolved in acetonitrile. To this solution was added 12.2 g (100 mmol) of anhydrous MgSO₄, 14g (100 mmol) of 4-chlorobenzaldehyde and 100 mmol of triethylamine. This mixture was stirred for 12 hours, concentrated to a small volume and diluted with 500 mL of ethyl acetate. The organic solution was washed successively with (0.1 %) ΝaHCO₃, (2N) NaOH, and brine solution. The organic was dried (anhy. MgSO₄), filtered and concentrated to afford 7.5g ofthe title compound. [M + H⁺] = 179.

Example-O-3) N-[4-chlorophenyl)methylene]-S-[2-[[(4- chlorophenyl)methylene]amino]ethyl]-2-methyl-D/L-cysteine methyl ester

A sample ofthe product of Example-O-2, N-{4-chlorophenyl)methylene]-S-[2-[[(4- chlorophenyl)methylene] amino] ethyl] -L-cysteine methyl ester (7.5 g, 17 mmol), in anhydrous THF was treated with 17 mmol of sodium bis(trimethylsilyl)amide at -78 °C under nitrogen, followed by 2.4g (17mmol) of methyl iodide. The solution was held at -78 °C for 4 hr and then warmed to room temperature with continuous stirring. The solvents were evaporated in vacuo and brine and ethyl acetate was added. The aqueous phase was extracted 3x EtOAc, and the combined organic layers were washed with 10% KHSO₄, water, and brine before it was dried (anhy. MgSO₄), filtered, and evaporated to afford the title compound.

Example-O-4) S-(2-aminoethyl)-2-methyl-D/L-cysteine, hydrochloride

A sample ofthe product of Example-O-3, N-[4-chlorophenyl)methylene]-S-[2-[[(4- chlorophenyl)methylene] amino] ethyl] -2-methyl-D/L-cysteine methyl ester (4.37 g, 10 mmol), was stirred and heated (60 °C) with 2Ν HCl overnight and the solution washed (3X) with ethyl acetate. The aqueous solution was freeze-dried to give the title compound.

Example O) A sample ofthe product of Example-O-4, S-(2-aminoethyl)-2-methyl-D/L- cysteine dihydrochloride (2.5 g (10 mmol), was dissolved in H₂O and the pH was adjusted to 10 with 1 N NaOH. Ethyl acetimidate hydrochloride (1.24 g, 10.0 mmol) was then added to the reaction mixture. The reaction was stirred 15-30 min, the pH was raised to 10, and this process repeated 3 times. The pH was reduced to 4 with HCl solution and the solution evaporated. The residue was purified on reverse phase HPLC with H₂O containing 0.05% trifluoroacetic acid as the mobile phase to afford the Example O title product. M + H = 220.

Example P

(2R)-2-Amino-3[[2-[(l-iminoethyl)amino]ethyl]sulfinyl]-2-methylpropanoic acid, dihydrochloride

A solution of S-[2-[(l-iminoethyl)amino]ethyl]-2-methyl-L-cysteine, dihydrochloride (Example I, 0.2g, 0.73 mmol) in 3 mL of water was stiπed and cooled to 0 °C and a solution of 3% H₂O₂ (0.8 mL, 0.73 mmol) in formic acid (0.4 mL, 0.73 mmol) was added in 0.3 mL portions. The cold bath was removed and the reaction mixture was stiπed at room temperature for 48 hours. The solution was concentrated in vacuo, diluted with of water (10 mL) and concentrated again to give the crude sulfone. This residue was chromatographed (C-18 reverse phase, with mobile phase H₂O containing 0.05% trifluoroacetic acid) to give the pure sulfone. The sulfone was treated with IM HCl (10 mL) and concentrated in vacuo to give 140 mg of a mixture of 2 diastereomers ofthe title compound as a colorless oil ofthe HCl salts. 1H NMR (300 MHz, D₂O) ? 1.5 (s, 2H), 1.6 (s, IH), 2.0 (s, 3H), 3.1 (m, 2H), 3.3 (m, 2H) 3.6 (m, 2H). HRMS calc. for C₈H₁₈N₃O₃S: 236.1069 [M+H⁺], found: 236.1024.

Example Q

(2R)-2-Amino-3[[2-[(l-iminoethyl)amino]ethyl]sulfonyl]-2-methylpropanoic acid dihydrochloride

A solution of S-[2-[(l-Iminoethyl)amino]ethyl]-2-methyl-L-cysteine dihydrochloride, the product of Example I, (0.15 g, 0.54 mmol) in 2 mL of water was cooled to 0 °C and a solution of 3% H₂O₂ (1.6 mL, 1.46 mmol) in formic acid (0.8mL, 14.6 mmol) was added. The cold bath was removed and the reaction mixture was stirred at room temperature for 18 hours. The solution was concentrated in vacuo, diluted with 10 mL of water and concentrated again to give the crude sulfoxide. The residue was diluted with 4 mL of water and was adjusted to pH 9 with 2.5 N NaOH. Acetone (5 mL) was added, followed by Boc₂O (0.2 g), and the reaction was stirred for 48 h at room temperature. The reaction mixture was adjusted to pH 6 with IM HCl and was concentrated in vacuo. This residue was chromatographed (C-18 reverse phase; 40 to 50% ACN: H₂O, 0.05% TFA) to give the pure Boc protected material. The fractions were concentrated in vacuo and the residue was treated with IN HCl (3 mL) for lh. The solution was concentrated to give 30 mg ofthe title compound as colorless oil. 1H NMR (400 MHz, D₂O) ? 4.0 (d, IH), 3.7 (d, IH), 3.6 (t, 2H), 3.5 (t, 2H), 2.1 (s, 3H), and 1.5 (s, 3H) ppm. HRMS calc. for C₈H₁₈N₃O₄S: 252.1018 [M + H⁺], found: 252. 0992.

Example R

(2S,5Z)-2-amino-6-methyl-7-[(l-iminoethyl)amino]-5-heptenoic acid, dihydrochloride

Example R-l)

E

A solution of triethyl-2-phosphonopropionate (6.5 mg, 27.1 mmol) in toluene (60 ML) was treated with 0.5 M potassium bis(trimethylsilyl) amide (50.0 ML, in toluene) and the resulting anion was condensed with the aldehyde product of Example U-3 by the method of Example U-4 (see Example U infra). This produced, after chromatography, 8 g of a 3:7 mixture respectively ofthe desired Z and E diesters.

(1H)NMR (300 MHz, CDC13) 6.7-6.8 ppm (m,lH), 5.9 ppm (m,lH), 4.9 ppm (m, IH), 4.2 ppm (q, 2H), 3.7 ppm (s, 3H), 2.5 ppm (m, IH), 2.2-2.3 ppm (m, 2H), 2.0 ppm (m, IH), 1.9 ppm (s, 3H), 1.8 ppm (s, 3H), 1.5 ppm (s, 18H), 1.3 ppm (t, 3H). Example R-2)

The product mixture of Example R-l (850 mg, 2.0 mmol) in Et O (30 mL) was reduced over a period of twenty minutes with diisobutyl aluminum/hydride (DIBAL) by the method of Example U-5 to produce the crude illustrated desired mixture of E-alcohol and unreduced Z-ester. This mixture was chromatographed on silica gel eluting with n-hexane : EtOAc (9:1) to n-hexane : EtOAc (1:1) providing samples ofthe Z-ester (530 mg) and the E-alcohol desired materials.

Z- ester: ^EQNMR (300 MHz, CDC13) 5.9 ppm (m,lH), 4.9 ppm ( , IH), 4.2 ppm (q, 2H), 3.7 ppm (s, 3H), 2.5 ppm (m, IH), 2.2-2.3 ppm (m, 2H), 1.9 ppm (s, 3H), 1.5 ppm (s, 18H), 1.3 ppm (t, 3H).

E- alcohol: (1H)NMR (300 MHz, CDC13) 5.35 ppm (m,lH), 4.9 ppm (m, IH), 3.95 ppm (s, IH), 3.7 ppm (s, 3H), 1.8-2.2 ppm (m, 6H), 1.6 ppm (s, 3H), 1.5 ppm (s, 18H).

Example R-3)

The product Z-ester of Example R-2 (510 mg, 1.2 mmol) in Et₂O (30 ML) was reduced over a period of two hours with diisobutyl aluminum/hydride (DIBAL) by the method of Example U-5 to produce the crude illustrated desired Z-alcohol. This material was chromatographed on silica gel eluting with n-hexane : EtOAc (9:1) to n-hexane : EtOAc (8:2) to yield 340 mg ofthe desired Z-alcohol product.

(1H)NMR (300 MHz, CDC1₃) ? 5.3 ppm (m,lH), 4.9 ppm (m, IH), 4.2 ppm (d, IH), 4.0 ppm (d, IH), 2.2 ppm (m, 3H), 1.95 ppm (m, IH), 1.8 ppm (s, 3H), 1.5 ppm (s, 18H).

Example R-4)

A CH₂C1₂ solution (5 ML) ofthe product alcohol of Example R-3 (340 mg, 0.9 mmol) was treated with triethylamine (151 mg, 1.5 mmol). To this solution cooled in an ice bath was added a CH₂C1₂ solution (1.5 ML) of methanesulfonyl chloride. After fifteen minutes the ice bath was removed and the reaction was stiπed at ambient temperature for 20 h. The reaction mixture was then washed with 10% KHSO₄, dried over Na₂SO₄, and stripped of all solvent under reduced pressure to produce 350 mg ofthe desired Z-allylic chloride.

^KQ MR (300 MHz, CDC1₃) ? 5.4 ppm (m,lH), 4.9 ppm (m, IH), 4.1 ppm (d, IH), 4.0 ppm (d, IH), 2.1 ppm (m, 3H), 1.95 ppm (m, IH), 1.8 ppm (s, 3H), 1.5 ppm (s, 18H).

Example R-5)

A suspension of potassium 3-methyl-l,2,4-oxa-diazoline-5-one in DMF is reacted with a DMF solution ofthe product of Example R-4 by the method of Example S-2 infra to produce the material.

Example R-6)

The product of Example R-5 is reacted with zinc in HO Ac by the method of Example U- 7 to yield the amidine.

Example R-7)

The product of Example R-6 was reacted with 4NHC1 in dioxane in glacial HO Ac to yield the amidine. Example R)

The product of Example R-7 is deprotected to yield the amino acid, dihydrochloride.

Example S

(2S,5E)-2-amino-6-methyl-7-[(l-iminoethyl)amino]-5-heptenoic acid, dihydrochloride

Example S-l)

The E-alcohol product of Example R-2 (1.3 g, 3.3 mmol) was reacted with triethylamine (525 mg, 5.2 mmol) and methanesulfonyl chloride (560 mg, 5.2 mmol) by the method of Example R-4 to yield 1.4 g ofthe desired E-allylic chloride.

(1H)NMR (400 MHz, CDC13) 5.5 ppm (m,lH), 4.9 ppm (m, IH), 4.0 ppm (s, 2H), 3.7 ppm (s, 3H), 2.1-2.3 ppm (m, 3H), 1.9 ppm (m, IH), 1.7 ppm (s, 3H), 1.5 ppm (s, 18H). Example S-2)

A suspension of potassium 3-methyl-l,2,4-oxa-diazoline-5-one (460 mg, 3.35 mmol) in 5 mL of DMF was treated with a DMF (15 mL) solution ofthe product of Example S-1. This reaction mixture was stirred at 50 °C for 17 h before an additional 50 mg (0.04 mmol) ofthe diazoline-5-one salt was added. Heating ofthe stirred reaction was continued for an additional 3 h before it was cooled to room temperature and diluted with 180 mL of water. This mixture was extracted with EtOAc and the extracts were diluted with 120 mL of n- hexane, washed with water, dried over Na₂SO₄ and stripped of all solvent under reduced pressure to yield 1.3 g ofthe material.

(1H)NMR (400 MHz, CDC13) 5.5 ppm (m,lH), 4.9 ppm (m, IH), 4.2 ppm (s, 3H),3.7 ppm (s, 3H), 2.2 ppm (m, 3H), 1.95 ppm (m, IH), 1.8 ppm (s, 3H), 1.5 ppm (s, 18H).

Example S-3)

The product of Example S-2 (460 mg, 1.0 mmol) was reacted with zinc in HO Ac by the method of Example U-7 (see Example U infra) to yield 312 mg ofthe desired amidine after HPLC purification. Example S)

The product of Example S-3 (77 mg, 0.2 mmol) was deprotected with 2N HCl by the method of Example U to yield 63 mg the E-amino acid, dihydrochloride.

Example T

(2S,5Z)-2-amino-7-[(l-iminoethyl)amino]-5-heptenoic acid, dihydrochloride

Example T-l) Methyl bis(trifluoroethyl)phosphonoacetate (4.77 g, 15 mmol) and 23.7g (90 mmol) of 18-crown-6 were dissolved in 80 mL of anhydrous THF and cooled to -78 ° C. To this soution was added 30 mL (15 mmol) of potassium bis(trimethylsilyl) amide, followed by 5.1g (14.7 mmol) of N,N-diBoc glutamic aldehyde methyl ester from Example U-3 (see Example U infra). After stirring for 30 minutes at -78 ° C, the reacion was quenched with aqueous KHSO₄ . Extraction ofthe reaction mixture with EtOAc and concentration afforded 2.95g (49%) ofthe desired compound. Mass spectra M + H = 402.

Example T-2) The product from Example T-l was reduced by the method of Example U-5 to afford the desired compound.

Example T-3) The product from Example T-2 was allowed to react with 3 -methyl- 1,2,4- oxadiazolin-5-one by the method of Example U-6 to afford the desired compound.

Example T-4) The product from Example T-3 was deprotected by the method of Example U-7 to afford the desired compound.

Example T) The product from Example T-4 was dissolved in 2 N HCl and heated at reflux. The reaction mixture was cooled and concentrated to afford 0.12 g ofthe desired product. H^!- NMR 1.8-2.0 (m, 2H); 2.05 (s, 3H); 2.15 (q, 2H); 3.75 (d, 2H); 3.9 (t, IH); 5.45 (m, IH); 5.6 (m, IH)

Example U

(2S,5E)-2-amino-7-[(l-iminoethyl)amino]-5-heptenoic acid, dihydrochloride

Example U-1) L-glutamic acid (6.0g, 40.78 mmol) was dissolved in methanol (100 mL). To the reaction mixture trimethylsilyl chloride (22.9 mL, 180 mmol) was added at 0 °C under nitrogen and allowed to stir overnight. To the reaction mixture at 0 ° C under nitrogen triethylamine (37 mL, 256 mmol) and di-tert-butyldicarbonate (9.8 g, 44.9 mmol) was added and stirred two hours. The solvent was removed and the residue was triturated with ether (200 mL). The triturated mixture was filtered. The filtrate was evaporated to an oil and chromatographed on silica, eluting with ethyl acetate and hexane, to give the mono boc L- glutamic diester (10.99 g, 98%). N(Boc)₂

O O

Example U-2)Mono boc L-glutamic acid (10.95 g, 39.8 mmol) was dissolved in acetonitrile (130 mL). To the reaction mixture 4-dimethylaminopyridine (450 mg, 3.68 mmol) and di- tert-butyldicarbonate (14.45 g, 66.2 mmol) was added and stiπed for 20 hours. The solvent was evaporated and the residue chromatographed on silica and eluting with ethyl acetate and hexane to give the di-boc-L-glutamic diester (14.63 g, 98 %).

N(Boc)₂

Example U-3) The product from Example U-2 (10.79 g, 28.7 mmol) was dissolved in diethyl ether (200 mL) and cooled in a dry ice bath to -80 C. To the reaction mixture Diisobutylaluminum hydride (32.0 mL, 32.0 mmol) was added and stiπed 25 minutes. The reaction mixture was removed from the dry ice bath and water ( 7.0 mL) was added. Ethyl acetate (200 mL) was added to the reaction mixture and stiπed 20 minutes. Magnesium sulfate (lOg) was added to the reaction mixture and stiπed 10 minutes. The reaction mixture was filtered through celite and concentrated to give a clear yellow oil (11.19g). The yellow oil was chromatographed on silica and eluting with ethyl acetate and hexane. The product (8.61, 87 %) was a clear light yellow oil. Mass Spectrometry: M+H 346, M+Na 378

(1H)NMR (400 MHz, CDC1₃) 9.74 ppm (s, IH), 4.85 ppm (m, IH), 3.69 ppm (s, 3H), 2.49 ppm (m, 3H), 2.08 ppm (m, IH), 1.48 ppm (s, 18H).

Example U-4) Triethyl phosphonoacetate (6.2 mL, 31.2 mmol) was dissolved in toluene (30 mL) and placed in an ice bath under nitrogen and cooled to 0 ° C. To the reaction mixture, potassium bis(trimethylsilyl) amide (70 mL, 34.9 mmol) was added and stiπed 90 minutes. To the reaction mixture the product from Example U-3 (8.51 g, 24.6 mmol) dissolved in toluene (20 mL) was added and stiπed 1 hour. The reaction mixture was warmed to room temperature. To the reaction mixture Potassium hydrogen sulfate ( 25 mL, 25 mmol) was added and stiπed 20 minutes. The mixture was extracted with ethyl acetate ( 3x100 mL), dried over Magnesium sulfate and concentrated to give a cloudy brownish yellow oil (12.11 g). The oil was chromatographed on silica, eluted with ethyl acetate and toluene to give a light yellow oil (7.21 g, 70 %).

Mass Spectrometry: M+H 416, M+NH₄ 433, -boc 316, -2 boc, 216.

(1H)NMR (400 MHz, CDC1₃) 6.88 ppm (m, IH), 5.82 ppm (d, IH), 4.81 ppm (m, IH), 5.76 ppm (s, 3H), 2.50ppm (m, 3H), 2.21 ppm (m, IH), 1.45 ppm (s, 18H).

Example U-5) The product from Example U-4 (5.0 g, 12.03 mmol) was dissolved in diethyl ether (100 mL) and placed in a dry ice bath and cooled to -80 °C. To the reaction mixture was added diisobutylaluminum hydride (21.0 mL, 21.0 mmol). And stiπed 30 minutes. To the reaction mixture water ( 10 mL) was added, removed from dry ice bath, and stiπed 60 minutes. To the reaction mixture magnesium sulfate (10 g) was added and stiπed 10 minutes. The reaction mixture was filtered over celite and concentrated to give a yellow oil (5.0 g). The oil was chromatographed on silica, eluted with ethyl acetate and hexane, to give a light yellow oil (2.14 g, 47 %).

Mass Spectrometry: M+H 374, M+NH₄ 391

(1H)NMR (400 MHz, CDC1₃) 5.63 ppm (m, 2H), 4.88 ppm ( m, IH), 4.02 ppm (s, 2H), 3.68 ppm (s, 3H), 2.12 ppm ( m, 4H), 1.47 ppm ( s, 18H).

Example U-6) The product from Example U-5 was dissolved in tetrahydrofuran (50mL). To the reaction mixture triphenyl phosphine on polymer (3.00 g, 8.84 mmol), oxadiazolinone ( 720 mg, 7.23 mmol), and azodicarboxylic acid dimethyl ester (1.17 g, 3.21 mmol) were added and stiπed six hours at room temperature. The reaction mixture was filtered over celite and concentrated to give a cloudy yellow oil (2.81 g). The oil was chromatographed on silica, eluting with ethyl acetate in hexane, to give a clear colorless oil (1.66 g, 68 %).

Mass Spectrometry: M+H 456, M+NH₄473, - boc 356, -2 boc 256

(1H)NMR (400 MHz, CDC1₃) 5.65 ppm (m, IH), 5.45 ppm (m,lH), 4.79 ppm (m, IH), 4.11 ppm (d, 2H), 3.68 ppm (s, 3H), 2.17 ppm (m, 4H), 1.47 ppm (s, 18 H).

Example U-7) Product from Example U-6 (300 mg, 0.66 mmol) was dissolved in a solution of acetic acid and water (10 mL, 25/75) containing zinc metal and sonicated for 3 hours. The reaction mixture was filtered over celite and chromatographed on reverse phase HPLC to give a clear colorless residue (13 mg, 4 %).

(1H)NMR (400 MHz, CDC1₃) 8.89 ppm (m, IH), 5.68 ppm (m,lH), 5.47 ppm (m, IH), 3.80 ppm (d, 2H), 3.71 ppm (s, 3H), 2.18 ppm (m, 4H), 1.41 ppm (s, 18 H).

Example U) The product from Example U-7 (13.0 mg, 0.031 mmol) was dissolved in 2 N HCl (1.22 mL, 2.44 mmol) and refluxed 1 hour. The reaction mixture was cooled, concentrated, to give a clear colorless oil (6.6 mg, 95%) Mass Spectrometry: M+H 200,

(1H)NMR (400 MHz, D₂0) 5.65 ppm (m, IH), 5.47 ppm (m,lH), 3.80ppm (t, IH), 3.72 ppm

(d, 2H), 2.0 ppm (m, 5H), 1.87 ppm (m, 2H).

Example V:

( R,2S)- -aminohexahydro-7-imino-lH-azepine-2-hexanoic acid, trihydrate hydrochloride

Example V-l)

A three neck 3L flask was purged with nitrogen before it was charged with cyclohexanone (1.27 mol, 132 mL) and 500 mL of toluene. This stirred mixture was cooled to 0 °C and 157.2 g (l.leq) of potassium t-butoxide was added. After stiπing this mix for 1 hr, a color and texture change was noted before a solution of 5-pentenyl bromide (1.27 mol, 136 mL) in 100 mL toluene was added dropwise over 1 h to the mechanically stiπed reaction mixture. The reaction mixture was allowed to warm to 25 °C and stir overnight. It was then diluted with 800 mL of 1 N KHSO₄ and the organic phase was dried (MgSO₄), filtered and evaporated to dryness to yield 208.5 g of crude product. This material was then purified by vacuum distillation (under water aspirator pressure) to give the title product in 47% yield.

1H NMR (CDC1₃, ppm): 1.0- 2.4 (m, 13H), 4.9-5.1 (m, 2H), 5.7-5.9 (m, IH). Example V-2)

The product of Example V-l (93.67 g, 0.563 mole) along with EtOH (600 mL), water (300 mL), NaOAc (101.67 g, 1.24 mole), andNH₂OH.HCl (78.31 g, 1.13 mole) were combined in a three neck 3 L flask. This stirred reaction mixture was refluxed for 16 h and then stiπed at 25 °C for another 24 h. All solvent was removed under reduced pressure and the residue was partitioned between diethylether (Et₂O, 500 mL) and water (200 mL). The aqueous layer was extracted 3 X 200 mL ether. The combined organic layers were dried over MgSO₄, filtered, and stripped in vacuo to give the title oxime (121.3 g, 100% crude yield).

1H NMR (CDC1₃, ppm): 1.2- 2.6 (m, 13H), 4.9-5.1 (m, 2H), 5.7-5.9 (m, IH).

Example V-3)

A three neck 3 L flask was purged with nitrogen and then charged with hexamethydisiloxane (471.7 mL, 2.2 moles), toluene (500 mL), and phosphorous pentoxide (203.88 g, 1.4 moles). This heterogeneous mixture was refluxed until a clear solution was obtained (about 1.5 h). After cooling this mixture to room temperature, the oxime product of Example V-l (102.1 g , 0.563 moles) in 200 mL of toluene was added to the above reaction mixture over a 1 h period at 25 °C. The reaction mixture was stiπed for another 4 - 6 h (checked by TLC: 50% EA in Hex, I₂) before it was poured into ice water with thorough mixing. To this ice slurry mixture was added 250 g of NaCl and the resulting mixture was adjusted to pH 5 by adding solid potassium carbonate. This sluπy was extracted with 3 X 500 mL of diethylether (Et₂O) and the combined organic fractions were dried over MgSO₄, filtered and stripped in vacuo to give the crude mixture of regioisomeric lactams (84.6 g).

Example V-4)

R-isomer

The product of Example V-3 was then subjected to chromatography (silica: acetonitrile) for purification and regioisomeric separation. From the crude sample, the 7-pentenyl regioisomer was isolated in 50% yield and after chiral chromatography, the desired single enantiomers were isolated in 43% yield each.

R-isomer:

Elemental analyses Calcd for C_nH₁₉NO: C, 71.99; H, 10.57; N, 7.63. Found: C, 71.97; H,

10.58; N, 7.52

1H NMR (CDC1₃, ppm): 1.3-1.6 (m, 7H), 1.75-1.9 (m, 2H), 1.95-2.15 (m, 3H), 2.4-2.5 (m,

2H), 3.25-3.35 (m, IH), 4.95-5.05 (m, 2H), 5.7-5.85 (m, IH).

¹³C NMR (CDC1₃, ppm): 23.166, 25.169, 29.601, 33.209, 35.475, 35.624, 36.783, 53.600,

114.976, 137.923, 177.703

[ ]²⁵ = +26.9° (CHCI₃) at 365nm.

S -isomer:

Elemental analyses Calcd for C_πH₁₉NO: C, 71.99; H, 10.57; N, 7.63. Found: C, 72.02; H,

10.61; N, 7.57

1H NMR (CDCI₃, ppm): 1.3-1.6 (m, 7H), 1.75-1.9 (m, 2H), 1.95-2.15 (m, 3H), 2.4-2.5 (m,

2H), 3.25-3.35 (m, IH), 4.95-5.05 (m, 2H), 5.7-5.85 (m, IH). ¹³C NMR (CDCI₃, ppm): 23.187, 25.178, 29.630, 33.230, 35.526, 35.653, 36.778, 53.621, 115.032, 137.914, 177.703

[ ]²⁵ = -25.7° (CHCl₃) at 365nm.

Example V-5)

The R-isomer product of Example V-4 (102.1 g, 0.56 mol), dry THF (800 mL), DMAP (68.9 g, 0.56 mol), Di-t-butyl dicarbonate (Boc₂O, 99 g, 0.45 mol) were combined in a three neck 3L flask purged with argon. The reaction mixture was warmed to 70 °C within 30 min before an additional 52.8 g of Boc₂O and 200 mL of dry THF were added. After 30 min. another 32 g of Boc₂O was added and the mixture was stirred for 1 h at 70 °C. Another 36 g of Boc₂O was added and the mixture was stiπed for 1 h. The reaction mixture was cooled to room temperature and stripped of THF at 18 °C to 20 °C under reduced pressure. A precipitate was filtered and washed with 100 mL of ethylacetate (EA) and discarded (~ 45 g). The EA filtrate was diluted with 500 mL of additional EA before it was washed with 500 mL of IN KHSO₄, 500 mL of saturated aq. NaHCO₃, and 500 mL of brine and then dried over anhydrous Na SO₄ for 12 h. This EA extract was then treated with 20 g of DARCO, filtered through celite topped with MgSO₄, and concentrated in vacuo to give 150 g of title product as a dark brown oil.

1H NMR (CDC1₃, ppm): 1.3-1.6 (m, 4H), 1.5 (s, 9H), 1.6-1.9 (m, 6H), 1.95-2.05 (m, 2H), 2.5-2.7 (m, 2H), 4.2-4.25 (m, IH), 4.95-5.05 (m, 2H), 5.7-5.85 (m, IH). Example V-6)

A three neck 3L flask containing the product of Example V-5 (150 g, 0.533) dissolved in 3 L of CH₂C1₂ was cool to -78 °C. A stream of O₃ was passed through the solution for 2.5 h until the color ofthe reaction mixture turned blue. Argon was then bubbled through the solution maintained at -60 °C to -70 °C until the solution became clear and colorless (~30 min.). Dimethylsulfide (DMS, 500 mL) was then added before the reaction was brought to reflux and this reflux was continued for 24 h. Another 100 mL of DMS was added and reflux was continued for 12 h. Another 100 mL of DMS was added and reflux continued for an additional 12 h. The solvent and excess DMS were then stripped on a rotary evaporator at 20 °C. The residual yellow oil obtained was diluted with 500 mL of DI water and extracted with 3 X 300 mL of EA. The EA layer was dried over anhydrous MgSO₄, treated with 20 g of DARCO, filtered through a thin layer of celite topped with anhydrous MgSO₄, and stripped of all solvent under reduced pressure to yield 156 g ofthe crude title product as orange yellow oil.

1H NMR (CDC1₃, ppm): 1.3-1.6 (m, 4H), 1.5 (s, 9H), 1.6-1.9 (m, 6H), 2.45-2.75 (m, 4H), 4.2-4.25 (m, IH), 9.75 (s, IH).

Example V-7)

To a sample of N-(Benzyloxycarbonyl)-alpha-phosphonoglycine trimethyl ester (160 g, 0.48 mol) dissolved in IL of dichloromethane (CH₂CI₂) and cooled to 0 °C was added a solution of DBU (110.29 g, 0.72 mol) in 100 mL of CH₂CI2. This clear colorless reaction mixture was stiπed for lh at 0 °C to 6 °C before the Boc-aldehyde product of Example V-6 (150 g, 0.53 mol) in 600 mL of CH₂θ₂ was added drop wise at -5 °C to -1 °C. The reaction mixture was stiπed for 30 min. at this temperature before it was slowly warmed to 10 °C in approximately 1 h. The reaction mixture was washed with IN KHSO₄ (500 mL), saturated aq. NaHCO₃ (200 mL) and 50 aq. NaCl (200 mL). The organic layer was then dried over anhydrous MgSO₄, treated with 40 g of DARCO, filtered through a thin layer of celite topped with anhydrous MgSO₄, and concentrated to give 258 g ofthe crude title product as an yellow oil. Chromatographic purification of this material gave 130 g (55%) ofthe pure title product.

Elemental analyses Calcd for C₂₆H₃₆N₂O₇: C, 63.96; H/7.42; N, 5.77. Found: C, 63.42; H,

8.16; N, 5.31.

1H MR (CDCI₃, ppm): 1.25 (m, 2H), 1.5 (s, 9H), 1.51-1.9 (bm, 8H), 2.25 (m, 2H), 2.5

(m, IH), 2.65 (m, IH), 3.75 (s, 3H), 4.12 (m, IH), 5.15 (s, 2H), 6.3 (bs, IH), 6.55 (t, IH),

7.45 (m,5H).

¹³C NMR (CDCI₃, ppm): 14.04, 22.62, 23.46, 24.08, 25.27, 27.89, 27.92, 28.34, 28.95,

31.81, 31.86, 32.05, 39.18, 52.31, 54.65, 67.27, 82.62, 128.07, 128.18, 128.46, 135.98,

136.82, 154.50, 164.92, 176.68.

[ ]²⁵ = +10.9° (CHCI3) at 365mn. Example V-8)

To a MeOH (1 L) solution ofthe product of Example V-7 (91.3 g, 0.19 mol) was added 2.5 g of S,S-Rh-DIPAMP catalyst followed by hydrogen. The hydrogenation was carried out at 25 °C in 1.5 h in a Parr apparatus. The reaction mixture was filtered through celite before concentrating to provide the crude title product (90 g, 98%) as a brown oil.

1H MR (CDC1₃, ppm): 1.35 (m, 4H), 1.5 (s, 9H), 1.55-1.95 (m, 10H), 2.4-2.7 (m, 2H), 3.75 (s, 3H), 4.2 (m, IH), 4.4 (m, IH), 5.1 (m, 2H), 5.35 (d, IH), 7.35 (m, 5H).

Example V-9)

To a solution ofthe product of Example V-8 (90 g,) in 200 mL of glacial acetic acid was added 200 mL of 4N HCl in dioxane. The reaction mixture was stiπed at 25 °C for 20 min. before it was stripped of all solvent under reduced pressure at 40 °C to give a red brown oil. This oily product was treated with 500 mL of water and extracted 2 X 300 mL of dichloromethane. The combined organic layer was washed with satd. sodium bicarbonate solution (100 mL), dried over magnesium sulfate, filtered and stripped of all solvent to give the crude title product. This material was chromatographed to provide 45 g (62%) ofthe pure title product. Elemental analyses Calcd for C₂₁H₃₀N₂θ₅: C, 64.02; H, 7.68; N, 7.17. Found: C, 63.10; H,

7.88; N, 6.60.

^!H NMR (CDC1₃, ppm): 1.2-2.0 (m, 14H), 2.45 (t, 2H), 3.25 (m,lH), 3.75 (s, 3H), 4.38 (m,

IH), 5.1 (s, 2H), 5.3 (d, IH), 5.45 (bs, IH), 7.35 (m, 5H).

¹³C NMR (CDCI₃, ppm): 14.09, 23.11, 24.89, 25.41, 29.53, 32.33, 35.52, 35.79, 36.68,

52.26, 53.51, 53.55, 53.60, 60.26, 66.86, 127.97, 128.05, 128.40, 136.18, 155.85, 172.85,

177.80.

[ ]²⁵ = -9.9° (CHCI3) at 365 nm.

Example V-10)

To a 45.0 g (0.115 mol) sample ofthe product of Example V-9 in 300 mL of dichloromethane purged with argon was added 23.0 g (0.121 mol) of triethyloxonium tetrafluoroborate. This mixture was stiπed for 1 h at 25 °C before 150 mL of satd. aq. sodium bicarbonate solution was added. The dichloromethane layer was separated, washed with 150 mL of 50% aq. NaCl solution, dried over sodium sulfate, filtered through celite and concentrated at 25 °C to give a clear yellow oil, 47.0 g (97%) ofthe title product

Elemental analyses Calcd for C₂₃H₃ N₂O₅: C, 60.01; H, 8.19; N, 6.69. Found: C, 65.13; H,

8.45; N, 6.64.

1H MR (CDCI3, ppm): 1.2 (t, 3H), 1.25-1.74 (m, 12H), 1.75-1.95 (m, 2H), 2.2-2.3 (m,

IH), 2.4-2.5 (m, IH), 3.1 (m, IH), 3.7 (s, 3H), 3.9-4.0 (m, 2H), 4.35 (m, IH), 5.1 (s, 2H),

5.25 (d, IH), 7.35 (m, 5H).

¹³C NMR (CDCI3, ppm): 14.23, 23.38, 25.01, 25.21, 26.10, 30.24, 32.16, 32.77, 33.92,

39.15, 52.22, 53.91, 58.05, 60.19, 66.92, 128.11, 128.33, 128.48, 136.27, 155.83, 166.29,

173.11, 177.64. Example V-l 1)

To 7.0 g (0.130 mol) of ammonium chloride in 500 mL methanol was added 31.2 g ofthe title material of Example V-10 (45.0 g, 0.107 mol). The reaction was refluxed at 65 °C for 5 h before all solvent was removed under reduced pressure to yield 40 g (87%) ofthe crude product as a foamy viscous mass. This material was purified by column chromatography to provide 37 g (81%) ofthe title product.

Elemental analyses Calcd for C₂ιH₃₁N₃O₄: C, 59.22; H, 7.57; N, 9.86; CI, 8.32. Found for C₂ιH₃₁N₃O₄ + 1.2 HCl + 0.5 H₂O: C, 57.20; H, 7.99; N, 9.66; CI, 9.62. IR (Neat, max cm^"1): 2935, 1716, 1669. ^lR NMR (CDC1₃, ppm): 1.2-2.0 (m, 13H), 2.5 (t, IH), 2.95 (m, IH), 3.4 (bs, IH), 3.7 (s, 3H), 4.3 (m, IH), 5.1 (s, 2H), 5.55 (d, IH), 7.3 (m, 5H), 8.75 (bs,lH), 8.9 (bs, IH), 9.5 (s, IH).

¹³C NMR (CDCI₃, ppm): 23.20, 24.95, 25.22, 28.94, 31.80, 32.05, 33.75, 34.89, 52.33, 53.76, 56.07, 66.83, 127.93, 128.04, 128.43, 136.26, 156.00, 172.24, 172.87. Mass (ESI): M/Z, 390. [ ]²⁵ = +31.5° at 365 nm.

Example V)

The title product of Example V-ll (36.0 g, 0.084 mol) in 1 L of 2.3 N HCl was refluxed for 3 h. After cooling to room temperature, the solution was washed with 2x150 mL of CH₂CI₂ and then stripped of all solvent in vacuo to give 25.6 g (96%) ofthe title amino acid product as a pale yellow foam. Elemental analyses Calcd for C₁₂H₂₃N₃O₂.2HCI: C, 46.02; H, 8.01; N, 13.39; CI 22.45. Found for C₁₂H₂₃N₃O₂ + 2.2 HCl + 0.1 H₂O: C, 42.76; H,8.02; N, 12.41; CI, 22.79. TR (Neat, . max, cm^"1): 2930, 2861, 1738,1665.

1H NMR (CD₃OD, ppm): 1.3-2.5 (m, 16H), 2.6 (dd, IH), 2.8 (t, IH), 3.65 (m, IH), 4.0 (t, IH), 7.85 (s, IH), 8.85 (s, IH), 8.95 (s, IH).

¹³C NMR (CD₃OD, ppm): 24.49, 25.67, 26.33, 29.71, 31.26, 32.45, 35.04, 35.87, 53.73, 57.21, 171.77, 173.96. UV, 282 nm, abs 0.015. Mass (M⁺¹) = 242. [ ]²⁵ = -47.4° (MeOH) at 365 nm. ee = 91 % as determined by CE at = 214 nm.

Example :

( S,2R)- -aminohexahydro-7-imino-lH-azepine-2-hexanoic acid, trihydrate hydrochloride

Example W-l)

The S-isomer product of Example V-4 (5.45 g, 0.030 mol) was converted to its Boc derivative by the method of Example V-5. After chromatography, this reaction yielded 6.3 g (75%) ofthe desired title product. 1HNMR (CDCI3, ppm): 1.3-1.6 (m, 4H), 1.5 (s, 9H), 1.6-1.9 (m, 6H), 1.95-2.05 (m, 2H), 2.5-2.7 (m, 2H), 4.2-4.25 (m, IH), 4.95-5.05 (m, 2H), 5.7-5.85 (m, IH).

Example W-2)

The product of Example W-l (6.3 g, 0.025 mol) was ozonized by the method of Example V-6 to produce 8.03 g ofthe crude title aldehyde that was used without further purification.

Example W-3)

The product of Example W-2 (8.03 g, 0.024 mol) was condensed with N- (Benzyloxycarbonyl)-alpha-phosphonoglycine trimethyl ester (7.9 g, 0.024 mol) utilizing the procedure of Example V-7 to produce 4.9 g (44%) ofthe desired title product after chromatography.

1H NMR (CDC1₃, ppm): 1.25 (m, 2H), 1.5 (s, 9H), 1.51-1.9 (bm, 8H), 2.25 (m, 2H), 2.5 (m, IH), 2.65 (m, IH), 3.75 (s, 3H), 4.15-4.25 (m, IH), 5.15 (s, 2H), 6.3-6.4 (bs, IH), 6.45- 6.55 (t, IH), 7.3-7.4 (m,5H). Example W-4)

The product of Example W-3 (4.8 g, 0.010 mol) was reduced in the presence of R,R-Rh-DIPAMP catalyst by the method of Example V-8 to produce 2.9 g (60%) ofthe desired title product after chromatography.

Example W-5)

The product of Example W-4 (2.9 g, 0.006 mol) was deprotected by treatment with HCl using the method of Example V-9 to produce 2.3 g (100%) ofthe desired title product.

1H NMR (CDC1₃, ppm): 1.3-2.0 (m, 14H), 2.45 (t, 2H), 3.25 (m,lH), 3.75 (s, 3H), 4.38 (m, IH), 5.1 (s, 2H), 5.3 (d, IH), 5.45 (bs, IH), 7.35 (m, 5H).

Example W-6)

The product of Example W-5 (0.56 g, 0.0015 mol) was alkylated with triethyloxonium tetrafluoroborate using the method of Example V-10 to produce 0.62 g (98%) ofthe desired title product. Example W-7)

The product of Example W-6 (0.62 g, 0.0015 mol) was treated with ammonium chloride in methanol using the method of Example V-ll to produce 0.50 g (88%) ofthe desired title product after chromatographic purification.

Example W-8)

The product of Example W-7 (0.37 g, 0.0009 mol) dissolved in MeOH was added to a Parr hydrogenation apparatus. To this vessel was added a catalytic amoxmt of 5%Pd/C. Hydrogen was introduced and the reaction was carried out at room temperature at pressure of 5 psi over a 7 hr period. The catalyst was removed by filtration and all solvent was removed under reduced pressure from the filtrate to produce 0.26 g (quantitative) ofthe desired title product.

Example W)

A solution ofthe product of Example W-8 dissolved in 2N HCl (30 mL) was maintained at reflux for 2 h before it was cooled to room temperature. All solvent was removed under reduced pressure and the residue was dissolved in 50 mL of water. This solution was again stripped of all solvent under reduced pressure before it was again dissolved in 12 mL of water and then lyophilized to generated 0.245 g (71%) ofthe title compound. Elemental analyses Calcd for C₁₂H₂₃N₃O₂.2.3 HCl.1.9 H₂O: C, 40.10; H, 8.16; N, 11.69; CI 22.69. Found for C₁₂H₂₃N₃O₂ + 2.1 HCl + 0.7 H₂O: C, 40.27; H, 8.28; N, 11.62; CI, 22.70. 1H NMR (CD₃OD, ppm): 1.4-2.1 (m, 16H), 2.6 (dd, IH), 2.8 (t, IH), 3.65 (m, IH), 4.0 (t, IH), 7.85 (s, IH), 8.45 (s, IH), 8.9 (s, IH).

¹³C NMR (CD3OD, ppm): 24.46, 25.64, 26.31, 29.69, 31.24, 32.54, 35.00, 35.83, 53.75, 57.20, 171.85, 173.93. [ ]²⁵ = +25.7° (MeOH) at 365 nm.

Example X:

( S,2S)- -aminohexahydro-7-imino-lH-azepine-2-hexanoic acid, trihydrate hydrochloride

Example X-l)

To a 22L round bottom flask equipped with overhead stiπer, half moon shape paddle, heating mantle, thermocouple, and a silver vacuum jacketed distillation column (5 plates) was charged cyclohexanone (4500.0 g, 45.85 mol), acetone dimethyl acetal (5252.6 g, 50.43 mol), ally! alcohol (6390.87 g, 110.04 mol) and p-toluene sulfonic acid (PTSA) (0.256 g, 0.001 mol). After the stirring was started (137 rpm) the pot was heated slowly with the initial set point being 70 °C. Heating was increased step wise to a final pot temperature of 150 °C. The decision to increase the reactor set point was made based on distillation rate. Ifthe rate of distillate slowed or stopped, additional heat was applied. The additional heating to 150 °C allowed the Claisen rearrangement to occur. After the pot temperature was raised to 150 °C and no distillate was observed, the heating mantle was lowered and the reaction mixture allowed to cool to 130 °C. The PTSA was then neutralized with 3 drops of 2.5 N NaOH. The vacuum stripping was then started with the heating mantle lowered away from the flask. Evaporative cooling was used to lower the pot temperature, and the pressure was gradually lowered to 40 mm Hg. When the pot temperature had decreased to -100 °C, the heating mantle was raised back into the proper position for heating. Unreacted cyclohexanone and low boiling impurities were distilled off. The pot temperature was slowly raised (the maximum temperature deferential between the pot and vapor was -12 °C). The product was isolated at 109-112 °C @ 40 mm Hg. Typical yields were 40-45%. Fractions which were <95% by area (GC) were combined and redistilled to afford the title product in a total yield of 55%.

1H NMR (CDC1₃, δ ppm): 5.8-5.6 (m, IH), 4.8-5.0 (m, 2H), 2.5-2.4 (m, IH), 2.3-2.1 (m, 3H),

2.1-1.2 (m, 7H).

¹³C NMR (CDC1₃, δ ppm): 212.53, 136.62, 116.32, 50.39, 42.18, 33.91, 33.52, 28.09, 25.10.

GC/MS m z = 138.

Example X-2)

Hydroxyl amine-O-sulfonic acid (91.8 g) dissolved in acetic acid (470 g) was added to a 1 L Bayer flask equipped with a mechanical stirrer, thermocouple, condenser chilled to 0 °C, and an addition funnel and heated to 70 °C. The allyl cyclohexone (100 g) was added dropwise in approximately 40 min to the above solution while maintaining the temperature between 70 and 78 °C. During the addition, the reaction appearance changed from a white slurry to a clear orange solution. After the addition, the reaction was heated and stirred for an additional 5 h at 75 °C. An IPC sample was taken each hour. After the reaction was complete, the acetic acid was stripped at 50 °C under reduced pressure on a rotary evaporator. Water (200 mL) was then added to the residue and the solution extracted with toluene (2 X 300 mL). The organic layers were combined, treated with water (150 ml) and stiπed for 10 min. A sodium hydroxide solution (79.4 g of 50 solution) was added until the aqueous layer turned basic (pH 12). The neutralization was carried out in the reactor by controlling the temperature below 40 °C. The layers were then separated and the toluene layer was passed through a filter to remove any solids or tarry material. The organic solution was then stripped at 50 °C under reduced pressure on a rotary evaporator. The residue was taken up in a mixture of toluene (510 mL) and heptanes (2040 mL) and heated to 60 °C in a 3 L reactor. A clear yellow-orange solution was obtained. The title product began to crystallize at 53 °C as the solution was slowly cooled to 5 °C while being stirred. The solid was filtered, washed with heptanes (50 mL) and dried over night at 40 °C under house vacuum to produce 66.3 g (60%) of title product as off-white crystals obtained. A portion of this material was recrystalhzed from toluene and heptane to generate the title product as a white crystalline solid.

1H MR (CDC1₃, δ ppm): 5.8-5.6 (m, IH), 5.5 (bs, IH), 4.8-5.0 (m, 2H), 3.4-3.3 (m, IH),

2.5-2.3(m, 2H), 2.3-2.1 (m, 2H) 2.0-1.2 ( m, 6H)

¹³C NMR (CDC1₃, δ ppm): 117.73, 133.83, 119.31, 52.88, 40.95, 37.20, 35.75, 29.96, 23.33.

GC/MS (EI mode) = 153. m.p. = 97-99 °C.

Example X-3)

R-isomer S-isomer

The racemic product mixture of Example X-2 was subjected to chiral chromatographic separation on a Chiralpac AS 20 urn column eluting with 100% acetonitrile. A 220 nM wavelength was employed in the detector. A sample loading of 0.08 g/mL of acetonitrile was used to obtain 90%> recovery of separated isomers each with >95% ee. A portion ofthe R- isomer material was recrystalhzed from toluene and heptane to generate the R-isomer title product as a white crystalline solid.

R-isomer: m.p. = 81 - 82 °C.

Example X-4)

A five necked flat bottom flask equipped with dropping funnel, thermometer and mechanical overhead stiπer was evacuated and purged with nitrogen three times. The R- isomer product lactam of Example X-3 (100.0 g, 0.653 mol), DMAP (7.98 g, 65 mmol) and N-diisopropylethyl amine (Hunigs base, 113.3 g, 0.876 mol) were dissolved in toluene (350 mL) and Di-tert-butyl dicarbonate (170.2 g, 0.78 mol) dissolved in toluene (100 mL) was added. (Note: the reaction works better, when 2.0 eq of Hϋnigs base were used). The mixture was heated to 65 °C (Note: Steady offgasing during the reaction was observed). After 1.5 h another 86.25 g of Di-tert-butyl-dicarbonate (0.395 mol) dissolved in toluene (50 mL) were added. Heating was continued for 17 h and IPC by HPLC showed 75 conversion. Another 42.78 g of Di-tert-butyl dicarbonate (0.196 mol) in toluene (30 mL) were added and the brown mixture was heated 5.5 h. After cooling to ambient temperature, the mixture was treated with 4M HCl (215 mL), and the aqueous layer was extracted with toluene (2x80 mL). The combined organic layers were washed with NaHCO₃ (170 mL) and 250 ml of water (Note: the internal temperature during the quench was controlled by external cooling with ice/water). Gas evolution was observed. The organic layer was evaporated to give 257.4 g brown liquid. This crude material was purified by plug filtration over SiO₂ (950 g) using toluene / EtOAc 9/1 (6 L) and toluene/AcOEt 1/1 (0.5 L) as eluent giving 139.5 g (51%) of the yellow liquid title product. Example X-5)

Example X-6)

Example If Into a 2-L stainless steel autoclave equipped with baffles and a six-bladed gas dispersing axial impeller was charged Rh(CO)₂(acac) (0.248 g, 0.959 mmol), BIPHEPHOS (structure shown below and prepared as described in Example 13 of US patent 4,769,498, 2.265 g, 2.879 mmol), the product of Example X-4 (N-(tert-butoxycarbonyl)-S-7-allylcaprolactam

BIPHEPHOS

(242.9 g, 0.959 mol), and toluene (965 g). The reactor was sealed and purged 100% carbon monoxide (8 x 515 kPa). The reactor was pressurized to 308 kPa (30 psig) with 100% carbon monoxide and then a 1 : 1 CO/H₂ gas mixture was added to achieve a total pressure of 515 kPa (60 psig). With vigorous mechanical agitation, the mixture was heated to 50 °C with a 1:1 CO/H₂ gas mixture added so as to maintain a total pressure of about 515 kPa (60 psig). After 22 h, the mixture was cooled to about 25 °C and the pressure was carefully released. Vacuum filtration ofthe product mixtxxre and evaporation ofthe filtrate under reduced pressure afforded a 267.7 g of a light yellow oil. Analysis by 1H ΝMR was consistent with essentially quantitative conversion ofthe starting material with about 96% selectivity to the corresponding aldehyde product of Example V-6. This oil was used without further purification in the following example.

1H NMR (CDC1₃) 1.47 (s, 9H), 1.6-1.80 (m, 9H), 1.84-1.92(m, IH), 2.41-2.58 (m, 3H), 2.61-2.71 (m, IH), 4.2 (d, J=5.2 Hz, IH), 9.74 (s, IH).

Example X-8)

Example lg To a sample of N-(Benzyloxycarbonyl)-alpha-phosphono glycine trimethyl ester (901.8 g, 2.7 mol) dissolved in CH₂C1₂ and cooled to 0 °C was added a solution of DBU (597.7 g, 3.9 mol) in CH₂θ₂. This clear colorless reaction mixture was stiπed for lh at 0 °C to 6 °C before a sample ofthe Boc-aldehyde product Example V-6 (812.0 g, 2.9 mol) in CH₂C1₂ was added drop wise at -5 °C to -1 °C. The reaction, work up, and purification was completed as described in Example V-7 to give 1550 g ofthe title product of Example V-7 containing a small amount of CH₂C1₂.

Example X-9)

To a MeOH (1 L) solution of the product of Example V-7 (100 g, 0.20 mol) was added 3 g of RR-Rh-DIPAMP catalyst. The hydrogenation was carried out at 25 °C in 1.5 h in a Parr apparatus. The reaction mixture was filtered through celite before concentrating to provide the crude Example X-9 title product as a brown oil (100 g).

1H NMR (CDCI₃, ppm): 1.35 (m, 4H), 1.5 (s, 9H), 1.6-1.9(m, 10H), 2.5-2.8 (m, 2H), 3.75 (s, 3H), 4.25 (m, IH), 4.45 (m, IH), 5.1 (m, 2H), 5.65 (d, IH), 7.35 (m, 5H). Example X-10)

To a solution ofthe product of Example V-8 (100 g) in 200 mL glacial acetic acid was added 25 mL 4N HCl in dioxane. The reaction mixture was stiπed at 25 °C for 20 min. before it was stripped of all solvent under reduced pressure at 40 °C to give 105 g of red brown oil. This oily product was treated with 500 mL of water and extracted 2 X 300 mL of dichloromethane. The combined organic layer was washed with satd. sodium bicarbonate solution (100 mL), dried over magnesium sulfate, filtered and stripped of all solvent to give 99.9 g ofthe title product as a red brown oil.

1H NMR (CDCI₃, ppm): 1.25-2.0 (m, 14H), 2.45 (t, 2H), 3.25 (m,lH), 3.7 (s, 3H), 4.35 (m, IH), 5.1 (s, 2H), 5.5 (d, IH), 6.45 (bs, IH), 7.35 (m, 5H). ee = 95% as determined by chiral HPLC.

Example X-ll)

To a 30.0 g (0.077 mol) sample ofthe product of Example X-10 in 600 mL dichloromethane purged with argon was added 15.7 g (0.082mol) of triethyloxonium tetrafluoroborate. This mixture was stiπed for 1 h at 25 °C before 300 mL of satd. aq. sodixim bicarbonate solution was added. The dichloromethane layer was separated, washed with 300 mL 50% aq. NaCl solution, dried over sodium sulfate, filtered through celite and concentrate at 25 °C to give a clear yellow oil, 31.2 g (-97%) ofthe title product. Elemental analyses Calcd for C₂₃H₃₄N₂O₅: C, 60.01; H, 8.19; N, 6.69. Found for C₂₃H₃₄N₂O₅

+ 0.5 H₂O: C, 64.66; H, 8.24_;N,6.59.

1H MR (CDC1₃, ppm): 1.2 5(t, 3H), 1.28-1.75 (m, 12H), 1.8-1.98 (m, 2H), 2.2-2.3 (m,

IH), 2.4-2.5 (m, IH), 3.1 (m, IH), 3.78 (s, 3H), 3.9-4.0 (m, 2H), 4.35 (m, IH), 5.1 (s, 2H),

5.25 (d, IH), 7.35 (m, 5H).

¹³C NMR (CDC1₃, ppm): 14.27, 23.36, 25.21, 25.53, 26.09, 30.22, 32.15, 32.73, 33.90,

39.14, 52.21, 53.89, 58.04, 60.33, 66.89, 128.11, 128.35, 128.48, 136.29, 155.86, 166.30,

173.14, 177.69.

IR (Neat, . max, cm^"1): 3295, 2920, 1739, 1680.

UV , 257 nm, abs 0.015.

[ ]²⁵ = +39.8° (CHC1₃) at 365 nm.

Example X-12)

To 4.2 g (0.078 mol) of ammonium chloride in 500 mL methanol was added 31.2 g ofthe title material of Example X-11. The reaction was refluxed at 65 °C for 5 h before all solvent was removed under reduced pressure to yield 29 g (92%) ofthe crude product as a foamy viscous mass. This material was purified by column chromatography to provide 23 g (70%) ofthe title product.

Elemental analyses Calcd for C₂₁H₃₁N₃O₄.lHCl) C, 59.28; H, 7.57; N, 9.89; CI, 8.39. Found

(For C₂₁H₃ιN₃O₄ + 1HC1 + 1 H₂O): C, 56.73; H, 7.74; N, 9.40; CI, 8.06.

IR (Neat, max cm^"1): 3136, 30348, 2935, 1716, 1669.

1H NMR (CDCI₃, ppm): 1.3-2.05 (m, 13H), 2.5 (t, IH), 2.98 (m, IH), 3.4 (bs, IH), 3.75 (s,

3H), 4.35 (m, IH), 5.1 (s, 2H), 5.5 (d, IH), 7.35 (m, 5H), 8.75 (s,lH), 9.0 (s, IH), 9.5 (s, IH). ¹³C NMR (CDC , ppm): 23.25, 25.01, 25.34, 29.01, 31.88, 32.26, 33.89, 35.06, 52.33,

53.73, 56.20, 66.89, 127.95, 128.06, 128.45, 136.27, 155.93, 172.27, 172.80.

UV , 257 nm, abs 0.009.

Mass (ESI): M/Z, 390.

[ ]²⁵ = -42.8° (MeOH) at 365 nm. ee = 96% as determined by chiral HPLC.

Example X)

The title product of Example X-12 (23 g) in 500 mL 2N HCl was refluxed for 5 h. All solvent was then removed in vacuo and the residue redissolved in water was washed with 2x300 mL of CH₂C1₂. The aqueous was then concentrated in vacuo to give 17 g (100%) of the light brown hygroscopic solid title product.

Elemental analyses Calcd for C₁₂H₂₃N₃O₂.2HCl: C, 45.86; H, 8.02; N, 13.37; CI 22.56. Found for C₁₂H₂₃N₃O₂ + 2.1 HCl + 0.7 H₂O: C, 43.94; H, 8.65; N, 12.52; CI, 22.23. IR (Neat, . max, cm^"1): 2936, 1742,1669.

1H NMR (CD₃OD, ppm): 1.3-2.1 (m, 16H), 2.6 (dd, IH), 2.8 (t, IH), 3.65 (m, IH), 4.0 (t, IH), 7.85 (s, IH), 8.4 (s, IH), 8.95 (s, IH).

¹³C NMR (CD₃OD, ppm): 24.49, 25.67, 26.33, 29.71, 31.26, 32.45, 35.04, 35.87, 53.73, 57.21, 171.77, 173.96. UV, 209 nm, abs 0.343. Mass (M⁺¹) = 242. [ ]²⁵ - +60.0° (MeOH) at 365 nm. ee = 92% as determined by CE at = 210 nm. Example Y

Example Y-l)

A solution of Example X-3 (3.0g, 0.015 mol) in methylene chloride and methanol (75/45 mL) was cooled to -78 °C in a dry ice bath. The reaction stiπed as ozone was bubble through the solution at a 3ml/min flow rate. When the solution stayed a consistent deep blue, the ozone was remove and the reaction was purged with nitrogen. To the cold solution was added sodium borohydride (2.14 g, .061 mol) very slowly to minimize the evolution of gas at one time. To the reaction was added glacial acetic acid slowly to bring the pH to 3. The reaction was then neutralized with saturated sodium bicarbonate. The oraganics were then washed 3x 50mL with brine, dried over magnesium sulfate anhydrous, removed under reduced pressure. The pale oil was run through a plug of silica (15 g) to afford the alcohol 5.15 g, 0.026 mol (64 %). C₉H₁₄N₂O₃.

1H NMR (CDCI3, ppm) 1.18 - 2.15(m, 8H), 3.59(m, 2H), 4.39(m, IH).

¹³C NMR (CDC1₃, ppm) 24.45, 25.71, 26.47, 32.56, 34.67, 51.16, 58.85, 160.66, 160.89. Example Y-2)

To a solution of Example Y-l (5.15 g, 0.026 mol) in methylene chloride (100 mL) at 0 °C in an ice bath was added carbon tetrabromide(10.78 g, 0.033 mol) . The solution was cooled to 0 °C in an ice bath. Then triphenylphosphine (10.23 g, 0.39 mol) was added portion wise as not to allow the temperature raise above 3 °C. The reaction was stiπed for 2 hours and the solvent was removed in vacuo. The crude was purified by flash chromatography to yield the bromide (5.9 g, 0.023 mol) in 87% yield.

Elemental analysis calculated for C₁₀H₁₆N₂O₃: C, 41.40; H, 5.02; N, 10.73; Br, 30.60. Found: C, 41.59; H, 5.07; N, 10.60, Br, 30.86.

1H NMR (CDC1₃, ppm) 1.50 - 2.60 (m, 9H), 2.99 (dd, IH), 3.35 (m, 2H), 4.41 (m, IH). ¹³C MR (CDC1₃, ppm) 23.89, 25.33, 26.04, 28.06, 31.59, 35.05, 52.79, 159.3, 160.2.

Example Y-3)

To a solution of Example Y-2 (5.71 g, 0.026 mol) in toluene (25 mL) was added triphenyl phosphine (7.17 g, 0.027 mol). The reaction refluxed in an oil bath for 16 hours. After cooling, the toluene was decanted from the glassy solid. The solid was triturated with diethyl ether overnight to afford the phosphonium bromide (10.21 g, 0.020 mol) in 90% yield. 1H MR (CDCI₃, ppm): 1.50 - 2.9 (m, 11H), 3.58 (m, IH), 4.16 (m, IH), 4.41 (m, IH),

7.6-8.0 (m, 15H).

¹³C NMR (CDCI₃, ppm): 24.43, 24.97, 25.50, 55.08, 55.27, 116.9, 118.1, 130.4, 130.6,

133.5, 135.1, 135.2, 159.4, 160.

³¹P NMR (CDC1₃, ppm) 26.0.

Example Y-4)

To a IL Round Bottom Flask was added N-benzyloxycarbonyl-D-homoserine lactone (97 g, 0.442 mol) in ethanol (500 mL). To the reaction was added solution of sodium hydroxide (IM, 50mL). The reaction was monitored by thin layer chromatography for 12 hours until the starting material had been consumed. Toluene (60 mL) was added and then solvent was removed in vacuo. The residue was carried on with no further purification.

Example Y-5)

The residue from Example Y-4 was suspended in DMF in a IL Round Bottom Flask. To the suspension was added benzyl bromide (76.9 g, 0.45 mol, 53.5 mL) and the mixture was stiπed for 1 hour. A sample was quenched and analyzed by mass spec to indicate the consumption ofthe starting material and that there was no lactone reformation. To the reaction was added IL of ethyl acetate and 500 mL of brine. The aqueous layer was washed 2 additional times with 500 mL of ethyl acetate. The organics were combined, dried over MgSO₄ and concentrated. Silica gel chromatography provided N-benzyloxycarbonyl-S- homoserine benzyl ester as a white solid (80 g).

Example Y-6)

To a 2L Round Bottom Flask was added pyridinium chlorochromate (187 g, 0.867 mol) and silica gel (197 g) suspended in CH2CI2 (600 mL). To the sluπy was added a solution of the product of Example Y-5 (80 g, 0.233 mol) in CH₂C1₂ (600 mL). The mixture was stirred for 4 hours. Thin layer chromatography indicated that the starting material was consumed. To the reaction was added 1 L of diethyl ether. The solution was then filtered through a pad of ceilite followed by a pad of silica gel. The solvent was removed in vacuo and the resulting oil was purified by silica gel chromatography to afford the aldehyde (58.8 g) in 38% overall yield.

MH⁺342.5, MH+NH₄ ⁺359.5.

1H NMR (CDCI₃, ppm) 3.15 (q, 2H), 4.12 (m, IH), 5.15 (s, 2H), 5.20 (s, 2H), 7.31 (m,

10H), 9.72 (s,lH).

Example Y-7)

To a 3L 3-neck flask was added the phosphonium salt from Example Y-3 (56.86 g, 0.11 mol) that had been dried over P₂O₅ under a vacuum in THF (IL). The slurry was cooled to - 78 °C in a dry-ice bath. To the cold slurry was added KHMDS (220 mL, 0.22 mol) dropwise so that the temperature did not rise above -72 °C. The reaction was stiπed at -78 °C for 20 minutes and then -45 °C for 2 hours. The temperature was then dropped back to -78 °C and the aldehyde (15.9 g, 0.047 mol) from Example Y-6 was added in THF (50 mL) dropwise over 45 minutes. The reaction was stiπed at -77 °C for 30 minutes then warmed to -50 °C for 1 hour before it was warmed to room temperature over 4 hours. To the reaction was added ethyl acetate (200 mL) and saturated ammonium chloride. The organics were collected, dried over MgSO₄ and concentrated in vacuo. The crude oil was purified on silica chromatography to afford the olefin compound (45.1 g) in 81% yield as a pale yellow viscous oil.

^lΪT NMR (CDC1₃, ppm) 1.4-2.6 (m,.10H), 2.92(d, IH), 4.17(m, IH), 4.38(m, IH), 5.05(q, 2H), 5.40(m, 2H), 7.3(m,10H).

¹³C NMR (CDC1₃, ppm) 29.49, 29.64, 31.32, 39.60, 49.56, 53.98, 61.01, 65.25, 124.14, 127.81, 128.20, 128.55, 128.79, 129.30, 130.96, 135.68, 137.31, 152.59, 157.57, 171.61.

Example Y)

To a 20 mL vial was added the product from Example Y-7 (19.77 g, 0.039 mol) in Dioxane (50 mL) and 4N aqueous HCl (250 mL). This solution was added a cat. amount of 10% Pd on carbon in a hydrogenation flask. The flask was pressurized with H₂ (50 psi) for five hours. The reaction was monitored by mass spec and the starting material had been consumed. The solution was filtered through a pad of celite and washed with water. The solvent was removed by lyophollization to afford the title compound (7.52 g) in 81% yield.

MH⁺ 242.2, MH+NH₄ ⁺ 259.2.

^!H NMR (CD₃OD ppm) 1.2-2.0 (m, 15H), 2.42 (d, IH), 2.65 (dd, IH), 3.49 (m, IH), 3.98

(t, IH), 7.26 (s), 8.05 (s), 8.35 (s).

¹³C NMR (CDC1₃, ppm) 24.43, 25.58, 26.00, 26.10, 32.75, 33.45, 35.31, 53.76, 54.55,

157.27, 175.13.

Example Z

Example Z-l)

To a 1 L 3-neck flask was added the phosphonium salt from Example Y-3 (21.21g, 0.041 mol) in THF (200 mL). The sluπy was cooled to -78 °C in a dry-ice bath. To the cold sluπy was added KHMDS (88 mL, 0.044 mol) dropwise so that the internal temperature did not rise above -72 °C. The reaction stiπed at -78 °C for 20 minutes then -45 °C for 1 hour. The temperature was then dropped back to-78 °C and the aldehyde (15.9 g, 0.047 mol) (prepared as in Example Y(4-6) using N-benzyloxycarbonyl-L-homoserine lactone) was added in THF (50 mL) dropwise over 45 minutes. The reaction was stiπed at -77 °C for 30 minutes then warmed to -50 °C for 30 minutes then warmed to room temperature over 4 hours. To the reaction was added ethyl acetate (100 mL) and saturated ammonium chloride. The organics were collected, dried over MgSO₄ and concentrated in vacuo. The crude oil was purified on silica chromatography to afford the olefin compound (9.0 g) in 45% yield as a pale yellow viscous oil.

1H NMR (CDC1₃, ppm) 1.4-2.6 (m, 10H), 2.92 (d, IH), 4.17 (m, IH), 4.38 (m, IH), 5.05 (q, 2H), 5.40 (m, 2H), 7.3 (m,10H).

¹³C NMR (CDC1₃, ppm) 29.49, 29.64, 31.32, 39.60, 49.56, 53.98, 61.01, 65.25, 124.14, 127.81, 128.20, 128.55, 128.79, 129.30, 130.96, 135.68, 137.31, 152.59, 157.57, 171.71.

Example Z)

To a 20 mL vial was added the product from Example Z-l in dioxane (5 mL) and 4N aqueous HCl (16 mL). This solution was added a cat. amount of 10% Pd on carbon in a hydrogenation flask. The flask was pressurized with H₂ (50 psi) for five hours. The reaction was monitored by mass spec and the starting material had been consumed. The solution was filtered through a pad of ceilite and washed with water. The solvent was removed by lyophilization to afford the title compound (98.7mg) in 79.4% yield.

MH⁺ 242.2, MH+NH4⁺ 259.2.

^!H NMR (CD₃OD, ppm) 1.2-2.0 (m, 15H), 2.42 (d, IH), 2.6 (dd, IH), 3.49 (m, IH), 3.98

(t, IH).

¹³C NMR (CDCI₃, ppm) 24.43, 25.58, 26.00, 26.10, 32.75, 33.45, 35.31, 53.76, 54.55,

157.27, 175.13.

Example AA (2S,4Z)-2-amino-6-[(2R)-hexahydro-7-imino-lH-azepin-2-yl]-4-hexenoic acid

Example AA-1)

(2S,4Z)-6-[(2R)-hexahydro-7-imino-lH-azepin-2-yl]-2- [[(phenylmethoxy)carbonyl]amino]- 4-hexenoic acid, phenylmethyl ester

To a 50 mL flask was added a sample of Example Z-l (1.5g, 2.97 mmol) in methanol (25mL). A 60% solution of glacial acetic acid (16 mL) was then added to the reaction mixture. A precipitate was observed. Additional methanol was added to dissolve the solid (ImL). To the reaction was then added zinc dust (0.200g). The reaction was sonicated for 4 hours during which the temperature was maintained at 37 °C. The reaction was monitored by TLC and MS until the starting material was consumed and a mass conesponding to the product was observed. The solution was decanted from the zinc and a 30% solution of acetonitrile/water (100 mL) was added to the filtrate. The reaction was purified with 52% acetonitrile/water in two runs on the Waters Preparatory ΗPLC [a gradient of from 20% to 70% acetonitrile over 30 minutes]. Lyophilization ofthe resulting product afforded the title material of Example AA-1 (l.Olg) in 73% yield as a white solid.

MΗ ^" 464.4, MΗ+Na⁺ 486.4.

1H NMR (CD₃OD, ppm): 1.2-2.0 (m, 8H), 2.42 (m, 2H), 2.6 (m, 5H), 3.49 (q, IH), 4.31 (t,

IH), 5.15 (s, 2H), 5.22 (s, 2H), 5.43 (q, IH), 5.59(q, IH), 7.25 (bs, 10H).

¹³C NMR (CDCI3, ppm): 24.37, 29.61, 30.76, 32.45, 33.73, 34.42, 55.40, 57.09, 68.06,

68.07, 122.3, 124.9, 128.76, 129.09, 129.28, 129.39, 129.51, 129.61, 155.71, 158.35, 173.90.

Example AA)

To a 250 mL flask was added the product of Example AA-1 (l.Og, 2.2mmol) in 4 M HCl (lOOmL). The reaction was refluxed overnight, monitored by MS until the starting material had been consumed and the mass for the product was observed. The reaction, without further work up was purified in two runs on the Water's prep reverse phase column using 18% acetonitrile/water [0% to 30% acetonitrile/water over 30 minutes]. Lyophilization ofthe combined fractions afforded the title product (0.34g) in 64% yield as a cream colored foam.

MH⁺ 240.3, MH+Na⁺ 486.4.

1H NMR (CD₃OD, ppm): 1.2-2.0 (m, 6H), 2.35 (m, 2H), 2.45 (dd, 2H), 2.69 (m, 2H), 3.61

(dt, IH), 3.98 (t, IH), 5.59(m, IH), 5.65 (m, IH).

¹³C NMR (CDCI3, ppm): 23.65, 24.66, 32.51, 32.84, 33.1, 33.25, 54.10, 56.1, 126.80,

129.33, 153.33, 172.52.

Example BB

(2S,4E)-2-amino-6-[(2R)-hexahydro-7-imino-lH-azepin-2-yl]-4-hexenoic acid

Example BB-1)

(2S,4E)-2-[[(phenylmethoxy)carbonyl]amino]-6-[(5R)-6,7,8,9-tetrahydro-3-oxo-3H,5H- [l,2,4]oxadiazolo[4,3-α]azepin-5-yl]-4-hexenoic acid, phenylmethyl ester

To a 250 L flask was added Example Z-l (2.0g, 3.9 mmol) and phenyl disulfide (0.860g, 3.9mmol) in a cyclohexane (70mL) / benzene(40mL) solution. Nitrogen was bubbled through the solution to purge the system of oxygen. The reaction was exposed to a short wave UN lamp for the weekend. The reaction was evaluated by normal phase ΗPLC (ethyl acetate/hexane). 71% ofthe trans isomer and 29% ofthe cis isomer was observed. The reaction was subjected to an additional 3 days of UN upon which 84% ofthe starting material converted to the trans isomer and 16% ofthe starting cis isomer remained. Purification by chromatography afforded Example BB-1 (0.956g) in 48% yield. MH^" 506.1, MH+NH4⁺ 523.2.

1H NMR (CD₃OD, ppm): 1.2-2.0 (m, 8H), 2.42 -2.6 (m, 6H), 2.91 (dd, IH), 4.19 (m, IH),

4.31 (dt, IH), 5.09 (s, 2H), 5.11 (s, 2H), 5.18 (dt, IH), 5.27(m, IH), 7.25 (bs, 10H).

Example BB-2)

(2S,4E)-6-[(2R)-hexahydro-7-imino-lH-azepin-2-yl]-2-[[(phenylmethoxy)carbonyl]amino]- 4-hexenoic acid, phenylmethyl ester, monohydrochloride

A sample ofthe product of Example BB-1 (0.956g, 1.9mmol) in MeOΗ (80mL) was deprotected by method of Example AA-1 with Zn dust (1.5g) and 60% ΗOAc/Η₂O (40 mL). The resulting product was purified by reverse phase chromatography to afford the title material (0.248g) in 28% yield.

Example BB)

The product of Example BB-2 (0.248g, 0.53mmol) was transformed into the title product by the method of Example AA using HCl (2mL), H₂O (2mL), CH₃CN (4mL). The crude product was purified by reverse phase chromatography to afford the title product of Example BB (0.073g) in 57% yield.

MH⁺ 240.3, MH+Na⁺ 486.4.

1H NMR (CD₃OD, ppm) 1.2-2.0 (m, 6H), 2.35 (t, 2H), 2.55-2.82 (m, 4H), 3.68 (dt, IH),

4.05 (t, IH), 5.65 (m, 2H). Example CC

(E)-2-amino-2-methyl-6-[(l-iminoethyl)amino]-4-hexenoic acid, dihydrochloride

Example CC-1)

DL- Alanine ethyl ester hydrochloride (5 g, 32.5 mmol) was suspended in toluene (50 mL). Triethyl amine (4.5 mL, 32.5 mmol) was added followed by phthalic anhydride (4.8 g, 32.5 mL). The reaction flask was outfitted with a Dean-Stark trap and reflux condenser and the mixture was heated at reflux overnight. Approximately 10 mL of toluene / water was collected. The reaction mixture was cooled to room temperature and diluted with aqueous NH₄C1 and EtOAc. The layers were separated and the aqueous layer was extracted with EtOAc (3X). The ethyl acetate extract was washed with brine, dried over MgSO₄, filtered and concentrated in vacuo to give the title phthalyl-protected amino ester as a white crystalline solid in near quantitative yield.

1H NMR (400 MHz, CDC1_3, ppm): 1.2 (t, 3H), 1.6 (d, 3H), 4.2 (m, 2H), 4.9 (q, IH), 7.7 (m, 2H), 7.9 (m, 2H)

Example CC-2)

Potassium phthalimide (18.5g, 0.1 mol) was added to a 250 mL round bottomed flask containing 1,4-butene dichloride (25g, 0.2 mol). The reaction mixture was heated to 150 °C for 1.5 h. The mixture was cooled to room temperature and was partitioned between brine and Et₂O. The organic layer was dried with MgSO₄, filtered and concentrated in vacuo. The residue was recrystalhzed from hot ethanol to give the title l-chloro-4-phthalimidobutene (8.9g, 39%) as orange crystals.

HRMS calcd. For C₁₂Hι₀ClNO₂: m/z = 236.0478 [M+H]. Found: 236.0449

1H NMR (300 MHz, CDC1₃ , ppm . 4.1 (d, 2H), 4.3 (d, 2H), 5.9 (m, 2H), 7.7 (m, 2H), 7.9

(m, 2H)

Example CC-3)

A sample of the product of Example CC-2 (2.3g, 9.8 mmol) was dissolved in acetone (50 mL). Nal (3.2g, 21 mmol) was added and the mixture was refluxed overnight. After cooling to room temperature, Et₂O was added and the mixture was washed sequentially with sodium thiosulfate and brine. The organic layer was dried with MgSO₄, filtered and concentrated in vacuo to give the title iodide (2.8g, 87.5%) as a light yellow solid that was used without further purification.

1H NMR (400 MHz, CDC1₃₎ ppm): 3.8 (d, 2H), 4.2 (d, 2H), 5.7 (m, IH), 6.0 (m, IH), 7.7 (m, 2H), 7.9 (m, 2H) Mass (M+l)=328

Example CC-4)

A solution of KHMDS (2.6 g, 13.3 mmol) in THF (50 mL) was cooled to -78 °C. A solution ofthe product of Example CC-1 (2.2 g, 8.87 mmol) in THF (15 mL) was added and 1,3- dimethyl-3,4,5,6-tetrahydro-2(lH)-pyrimidinone (DMPU, 1.0 mL, 8.87 mL) was added immediately thereafter. After the solution was stiπed at -78 °C for 40 minutes, a solution of the product of Example CC-3 (2.9 g, 8 87 mmol) in THF (15 mL) was added. The flask was removed from the cold bath and was stiπed at room temperature for 3h. The reaction mixture was partitioned between saturated aqueous NaHCO₃ and EtOAc. The organic extract was washed with brine, dried over MgSO₄, filtered and concentrated in vacuo to give the desired bis-pththalyl protected amino ester as a yellow solid. This residue was chromatographed on silica gel (1:1 hexanes: EtOAc) and gave 1.4 g (35 %) ofthe title material as a white solid.

1H NMR (300 MHz, CDC1₃, . ppm 1.2 (t, 3H), 1.6 (d, 3H), 2.8 (dd, IH), 3.1 (dd, IH), 4.2 (m, 4H), 5.6 (m, IH), 5.8 (m, IH), 7.6 (m, 4H), 7.7 (m, 2H), 7.9 (m, 2H) Mass (M+H)=447

Example CC-5)

H₃C NH₂ H₂N ^^ ^-^ C0₂H

The product of Example CC-4 (0.78 g, 1.76 mmol) was dissolved in a mixture of formic acid (lOmL, 95%) and HCl (20 mL, concentrated HCl) and was refluxed for 3 days. The reaction mixture was cooled to 0 °C and filtered to remove phthalic anhydride. After concentrating in vacuo (T < 40 °C), the title unsaturated alpha methyl lysine was obtained as a white solid (0.38g, 95 %), which was used without further purification. 1H NMR (300 MHz, D₂O, ppm): 1.4 (s, 3H), 2.4 (dd, IH), 2.6 (dd, IH), 3.5 (d, 2H), 5.7 (m, 2H) Mass(M+H)=317

Example CC)

The product of Example CC-5 (0.2 g, 0.86 mmol) was dissolved in H₂O (8 mL) and was brought to pH 9 with 2.5 NNaOH. Ethyl acetimidate - HCl (0.42 g, 3.4 mmol) was added in four portions over 1 h. After lh, the mixture was acidified to pH 4 with 10% HCl and was concenfrated in vacuo. The residue was then passed through a water-washed DOWEX 50WX4-200 column (H form, 0.5 N NH₄OH eluent). The residue was concentrated in vacuo, acidified to pH 4 with 10 % HCl, and concentrated to give the title product (17 mg, 6 %) as an oil.

HRMS calcd. For C₉H₁₇N₃O₂: m/z = 200.1399 [M+H]. Found: 200.1417

1H NMR (400 MHz, D₂O, . ppm): 1.4 (s, 3H), 2.1 (s, 3H), 2.5 (dd, IH), 2.6 (dd, IH), 3.8 (d,

2H), 5.6 (m, 2H)

Example DD

(R, jE)-2-amino-2-methyl-6-[(l-iminoethyl)amino]-4-hexenoic acid, dihydrochloride

Example DD-1)

(2S, 4S)- 3-Benzoyl-2-(tert-butyl)-4-methyl-l,3-oxazolidin-5-one was prepared according to Seebach's procedure. Seebach, D.; Fadel, A. Helvetica Chimica Acta 1985, 68, 1243. Example DD-2)

A solution of KHMDS (0.65g, 3.24 mmol), DMPU (0.33 mL, 2.7 mmol) and THF (40 mL) was cooled to -78 °C. A solution of (2S, 4S)- 3-benzoyl-2-(tert-butyl)-4-methyl-l,3- oxazolidin-5-one (Example DD-1) (0.70g, 2.7 mmol) in THF (10 mL) was added dropwise. After 45 min, a solution ofthe product of Example CC-3 (0.88g, 2.7 mmol) in THF (10 mL) was added. The reaction mixture was stiπed at room temperature for 2 h and quenched with saturated aqueous NaHCO₃. The layers were separated and the aqueous layer was extracted with EtOAc. The organic layers were combined and washed with brine, dried over MgSO₄, filtered and concentrated in vacuo. The resulting yellow oil was chromatographed on silica gel (9:1 then 4:1 hexanes / ethyl acetate) to give the title protected unsaturated alpha methyl D-lysine (0.26g, 20 %) as a colorless oil.

HRMS calcd. For C₂₇H2₈N₂O₅: m/z = 461.2076[M+H]. Found: 461.2033

1H NMR (400 MHz, CDC1₃, . ppm . 0.9 (s, 9H), 1.5 (s, 3H), 4.3 (m, 2H), 5.5 (m, 2H), 5.6 (m,

2H), 6.1 (m, IH), 7.5 (m, 5H), 7.7 (m, 2H), 7.9 (m, 2H)

Example DD-3)

H₃C NH₂

- 2HCI

H₂N C0₂H

The product of Example DD-2 (0.255 mg, 0.55 mmol) was dissolved in 6N HCl (6 mL) and formic acid (6 mL) and was heated to reflux for 24 h. The reaction mixture was cooled to room temperature and concentrated in vacuo. The residue was suspended in water and washed with CH₂CI₂. The aqueous layer was concentrated and passed through a water- washed DOWEX 50WX4-200 column (H foπn, 0.5 N NH₄OH eluent). The residue was concentrated in vacuo, acidified to pH 4 with 10 % HCl, and concentrated to give the title unsaturated D-lysine (71 mg, 55 %) as an oil which was used without further purification.

1H NMR (400 MHz, D₂O, ppm . 1.4 (s, 3H), 2.5 (dd, IH), 2.6 (dd, IH), 3.4 (d, 2H), 5.6 (m, 2H), 5.7 (m, 2H)

Example DD)

The product of Example DD-3 (13 mg, 0.056 mmol) was dissolved in H₂O (5 mL) and was brought to pH 9 with 2.5 N NaOH. Ethyl acetimidate - HCl (27 mg, 0.2 mmol) was added in four portions over 2 h. After 2h, the mixture was acidified to pH 4 with 10% HCl and was concentrated in vacuo. The residue was passed through a water-washed DOWEX 50WX4- 200 column (H form, 0.5 N NH₄OH eluent). The residue was concentrated in vacuo, acidified to pH 4 with 10 % HCl, and concentrated to give the title product (45 mg) as an oil.

HRMS calcd. For C₉H₁₇N₃O₂: m/z = 200.1399 [M+H]. Found: 200.1386

1H NMR (400 MHz, D₂O, ppm): 1.4 (s, 3H), 2.1 (s, 3H), 2.5 (dd, IH), 2.6 (dd, IH), 3.8 (d,

2H), 5.6 (m, 2H)

Example E

(S, E)-2-amino-2-methyl-6-[(l-iminoethyl)amino]-4-hexenoic acid, dihydrochloride

Example EE-1)

H₃Q

Br -N^O

(2R, 4R)-3-Benzoyl-2-(tert-butyl)-4-methyl-l,3-oxazolidin-5-one was prepared according to Seebach's procedure. Seebach, D.; Fadel, A. Helvetica Chimica Acta 1985, 68, 1243.

Example EE-2)

A solution ofthe (2R, 4R)-3-benzoyl-2-(tert-butyl)-4-methyl-l,3-oxazolidin-5-one product of Example EE-1 (2.0g, 7.6 mmol) in THF (50 mL) was cooled to -78 °C. A -78 °C solution of KHMDS (0.65g, 3.24 mmol) in THF (25 mL) was added dropwise. After 30 min, a solution ofthe product of Example CC-3 (2.8 g, 8.6 mmol) in THF (25 mL) was added. The reaction mixture was stirred at room temperature for 1 h and quenched with saturated aqueous NaHCO₃. The layers were separated and the aqueous layer was extracted with EtOAc. The organic layers were combined and washed with brine, dried with MgSO₄, filtered and concentrated in vacuo. The resulting orange oil was chromatographed on silica gel (9:1 then 4:1 hexanes / ethyl acetate) to give the protected title unsaturated alpha methyl L-lysine (0.5g, 15 %) as a white solid.

HRMS calcd. For C₂₇H₂₈N₂O₅: m/z = 461.2076[M+H]. Found: 461.2043

1H NMR (400 MHz, CDC1₃, . ppm): 0.9 (s, 9H), 1.5 (s, 3H), 4.3 (m, 2H), 5.5 (m, 2H), 5.6

(m, 2H), 6.1 (m, IH), 7.5 (m, 5H), 7.7 (m, 2H), 7.9 (m, 2H) Example EE-3)

H₂N Me

^■ 2 HCl

H₂N "C0₂H

The product of Example EE-2 (0.5 g, 1 mmol) was dissolved in 12N HCl (10 mL) and formic acid (5 mL) and this mixture was heated to reflux for 12 h. The reaction mixture was cooled in the freezer for 3h and the solids were removed by filtration. The residue was washed with CH₂C1₂ and EtOAc. The aqueous layer was concentrated in vacuo and gave the title unsaturated alpha methyl L-lysine (0.26 g, 99 %) as an oil which was used without further purification.

1H NMR (300 MHz, D₂O, ppm): 1.4 (s, 3H), 2.5 (dd, IH), 2.6 (dd, IH), 3.4 (d, 2H), 5.7 (m, 2H)

Example EE)

The product of Example EE-3 (0.13 g, 0.56 mmol) was dissolved in H₂O (1 mL) and was brought to pH 9 with 2.5 N NaOH. Ethyl acetimidate - HCl (0.28 g, 2.2 mmol) was added in four portions over 1 h. After lh, the mixture was acidified to pH 4 with 10% HCl and was concentrated in vacuo. The residue was and passed through a water-washed DOWEX 50WX4-200 column (0.5 N NH₄OH eluent). The residue was concentrated in vacuo, acidified to pH 4 with 10 % HCl, and concentrated to give the title product as an oil (40 mg).

HRMS calcd. For C₉H₁₇N₃O₂: m/z = 222.1218 [M+Na]. Found: 222.1213

1H MR (300 MHz, D₂O, ppm): 1.4 (s, 3H), 2.1 (s, 3H), 2.4 (dd, IH), 2.6 (dd, IH), 3.8 (d,

2H), 5.6 (m, 2H) Example FF

2-amino-2-methyl-6-[(l-iminoethyl)amino]-4-hexynoic acid, dihydrochloride

Example FF-1)

The N-boc-l-amino-4-chlorobut-2-yne was prepared following the procedure described in Tetrahedron Lett. 21, 4263 (1980).

Example FF-2)

H₃CX 0₂Me Ph^ Ph

Methyl N-(diphenylmethylene)-L-alaninate was prepared by following the procedure described in J. Org. Chem., 47, 2663 (1982).

Example FF-3)

Dry THF (lOOOmL) was placed in a flask purged with argon and 60% NaH dispersed in mineral oil (9.04 g, 0.227 mol) was added. To this mixture was added the product of Example FF-2 (30.7 g, 0.114 mol). The reaction mixture was then stiπed at 10 °C - 15°C for 30 min. Potassium iodide (4 g) and iodine (2 g) were added and immediately followed by the addition ofthe product of Example FF-2 (23 g, 0.113 mol in 200 mL THF) in 30 min. The reaction mixture was then stiπed at 55 °C until the starting material disappeared (~ 2 h). The reaction mixture was then cooled to room temperature and the solvent was evaporated. Ethyl acetate (500 mL) was added and the mixture was carefully washed with 2 X 200 mL deionized water. The organic layer was dried over anhydrous MgSO₄, filtered and evaporated to give 44 g of crude product. Purification by chromatography using 20% ethyl acetate in hexane afforded the title protected unsaturated alpha-methyl lysine (28 g, 57%).

AnaLCalcd for C₂₆H₃oN₂O₄ and 0.5 ethylacetate: C,70.42; H, 7.14; N, 5.91. Found: C,

70.95; H, 7.73; N, 6.09

IR (Neat, max, cm^"1): 2981, 1714, 1631

1H NMR (CDC1₃, ppm): 1.28 (s, 9H), 1.4 (s, 3H), 2.65-2.76(m, 2H), 3.15 (s, 3H), 3.7 (bs,

2H), 4.6 (bs, IH), 6.95-7.4 (m, 10H)

¹³C NMR (CDCI₃, ppm): 24.29, 28.33, 28.39, 33.24, 51.60, 53.55, 127.79, 127.97, 128.26,

128.36, 128.43, 128.54, 128.66, 130.05, 130.22, 132.39

Mass (M+l) = 435

DSC purity: 261.95 °C

Example FF-4)

The product of Example FF-3 (16 g, 0.0368 mol) was dissolved in IN HCl (300 mL) and stiπed at 25 °C for 2 h. The reaction mixture was washed with ether (2 x 150mL) and the aqueous layer separated and decolorized with charcoal. Concentration afforded ~9 g (100% yield) ofthe deprotected unsaturated alpha-methyl lysine ester FF-4 as white foamy solid.

AnaLCalcd for C₈H₁₄N₂O₂ containing 2.26 HCl and 1.19 H₂O: C,35.06; H, 6.86; N, 10.22; CI, 29.24. Found: C, 35.31; H, 7.38; N, 10.70; CI, 29.77 1H NMR (D₂O, ppm): 1.56 (s, 3H), 2.8-3.0 (2 dt, 2H), 3.75(s, 2H), 3.79 (s, 3H) ¹³C MR (D₂O, ppm): 23.89, 29.81, 32.05, 57.08, 61.90, 79.57, 82.43, 173.92 Mass (M+l) = 171

DSC purity: 114.22 °C

UV = 206 nm,abs 0.013

[a]₂₅ in methanol = 0 at 365 nm

Example FF-5)

The product of Example FF-4 (2.43 g, 0.01 mol) was dissolved in deionized water (25 mL). A solution of NaOH (400 mg, 0.01 mol) in deionized water (25 mL) was added at 25°C to bring the pH to -7.95 and stirring was continued another 10 min. Ethylacetimidate hydrochloride (988 mg, 0.008 mol) was added to the reaction mixture with simultaneous adjustment ofthe pH to - 8.5 by adding IN NaOH. The reaction mixture was stiπed at pH 8 to 8.5 for 3 h following acetimidate addition. IN HCl was added to the reaction mixture (4.1 pH). The solvent was evaporated at 50 °C to afford a yellow crude hygroscopic residue (4 g, >100% yield). Purification was carried out on the Gilson chromatography system using 0.1% AcOH/CH₃CN/H₂O.

AnaLCalcd for C₁₀H₁₇N₃O₂ containing 2.25 HCl and 1.7 H₂O: C, 37.08; H, 7.05; N, 12.97;

CI, 24.63. Found: C, 37.01; H, 6.79; N, 12.76; CI, 24.87

IR (Neat, max, cm^"1): 2953, 2569, 1747, 1681, 1631

1HNMR (D₂O, ppm): 1.52 (s, 3H), 2.12 (s, 3H), 2.74-2.96 (2 dt, 2H), 3.75 (s, 3H), 3.95 (t,

2H)

¹³C NMR (D₂O, ppm): 23.89, 29.81, 32.05, 57.08, 61.90, 79.57, 82.43, 173.92

Mass (M+l) = 212 Example FF)

The product of Example FF-5 (100 mg, 0.0005 mol) was dissolved in 8N HCl (20 mL) and stiπed for 10 h at reflux. The reaction mixture was cooled to room temperature and the aq. HCl was evaporated on rotavap. The residue was dissolved in deionized water (lOmL) and water and reconcenfrated under vacuum to afford the title product as a yellow glassy solid in almost quantitative yield (88 mg).

AnaLCalcd for C₉H₁₅N₃O₂ containing 2.4 HCl and 1.8 H₂O: C, 34.08; H, 6.67; N, 13.25; CI,

26.83. Found: C, 34.32; H, 6.75; N, 13.63; CI, 26.47

IR (Neat, max, cm^"1): 1738, 1677, 1628, 1587

1H NMR (D₂O, ppm): 1.6 (s, 3H), 2.24 (s, 3H), 2.8-3.0 (2 dt, 2H), 4.1 (s, 2H)

¹³C NMR (D₂O, ppm): 21.22, 24.10, 29.88, 34.58, 80.04, 80.99, 128.39, 168.07, 176.13

Mass (M+l) = 198

Example GG

(2R/S,4-Z)-2-amino-2-methyl-7-[(l-iminoethyl)amino]-4-heptenoic acid, dihydrochloride

Example GG-1) 5,6 dihydropyran-2-one (49.05g, 0.5mol) was dissolved in 200 mL of water. Potassium hydroxide (35g, 0.625 mol) was added and the reaction mixture stiπed at ambient temperature for 5 hours. The solvent was removed in vacuo to yield a colorless glassy solid (65g, 84%) that was characterized by NMR to be predominantly the cis isomer of the title compound.

1H NMR (CDC1₃) : 2.7 (m, 2H), 3.6 (t, 2H), 5.8-5.85(m, IH), 5.9-5.97 (m, IH).

Example GG-2) The product of Example GG-1 was dissolved in 100 mL of dimethyl formamide. Methyl Iodide (52mL, 0.84 mol) was then added resulting in an exotherm to 40 °C. The reaction mixture was stiπed at room temperature for 10 hours and partitioned between 150 mL of ethylacetate / diethylether in a 20/ 80 ratio and ice water. The aqueous layer was separated and re-extracted with 100 mL of diethyl ether. The organic layers were combined , dried (Na₂SO₄), filtered and stripped of all solvent to yield the desired methyl ester product (40g, 71%). This material was dissolved in 200 mL of methylene chloride and the solution cooled to 0°C. Tertiarybutyl dimethylsilylchloride, triethylamine and dimethylaminopyridine were added. The reaction mixture was slowly warmed to room temperature and st πed for 10 hours under nitrogen. The reaction was extracted with 100 mL of IN aqueous potassium bisulfate solution. The organic layer was washed with 2X 100 mL of brine and then with 3 X 150 mL of water. The organic layer was dried (Na₂SO ), filtered and stripped to yield 42g (56%) ofthe title material.

1H NMR (CDCI3) : 0.02 (s, 6H), 0.085 (s, 9H), 2.8-2.85 (m, 2H), 3.65 (s, 3H), 3.66-3.7 (m 2H), 5.8 (m, IH), 6.3 (m, IH)

Example GG-3) The material from Example GG-2 was dissolved in 25 mL of toluene and cooled to 0°C. Diisobutylaluminum hydride (1.0 M in toluene, 32 mL, 48 mmol) was added dropwise maintaining the temperature between 5 and -10 °C. The reaction mixture was stiπed for 1.5 hours between 6 and -8 °C before it was cooled to -25 °C. To this mixture was added 100 mL of 0.5N sodium potassium tartarate. The reaction mixture was allowed to warm up to room temperature and stiπ for an hour. A gelatinous precipitate was formed which was filtered. The aqueous was extracted with 2 X 100 mL EtOAc. The combined organic layers were dried (sodium sulfate), filtered and concentrated in vacuo to yield title product (3.45g, 66%) as a colorless oil.

1H NMR (CDC1₃) : 0.02 (s, 6H), 0.085 (s, 9H), 2.25-2.32 (m, 2H), 2.6 (bs, IH), 3.6 (t, 2H), 4.08 (d, 2H), 5.45-5.55 (m, IH), 5.7-5.75 (m, IH)

Example GG-4) The product (8g, 37 mmol) from Example GG-3 was dissolved in 100 mL methylene chloride and this solution was cooled to 0 °C. Methanesulfonyl chloride was then added and this mixture was stined for 5 min. Triethylamine was then added. The temperature maintained between 0 and -10 °C during the addition ofthe aforementioned reagents. The reaction mixture was subsequently warmed up to room temperature and stined for 24 hours. It was then extracted with 100 mL of 50% aqueous sodium bicarbonate solution. The organic layer was washed with 100 mL of saturated aqueous brine solution, dried (sodium sulfate), filtered and stripped in vacuo to yield the title material (8.2g, 94%).

1H NMR (CDCI3) : 0.02 (s, 6H), 0.085 (s, 9H), 2.25-2.32 (m, 2H), 3.6 (t, 2H), 4.08 (d, 2H), 5.6-5.7 (m, 2H)

Example GG-5) A solution of N-p-chloro phenylimine alanine methyl ester (8.85g, 34 mmol) dissolved in 59 mL of tetrahydrofuran was purged with Argon. NaH (1.64g, 41mmol) was added whereupon the solution turned bright orange and subsequently a deep red. A solution ofthe title material from Example GG-4 (8g, 34 mmol) in 40 mL of tetrahydrofuran was added to the above anionic solution. An exotheπn was observed raising the temperature to almost 40°C. The reaction mixture was maintained between 48 and -52 °C for 2 hours. It was then cooled to room temperature and filtered. Filtrate was stripped in vacuo to yield the title material (8.4g, 50% crude yield) as a yellow oil.

^XH MR (CDC1₃) : 0.02 (s, 6H), 0.085 (s, 9H), 1.45 (s, 3H), 1.6 (s, IH), 2.2-2.25(m, 2H), 2.65 (d, 2H), 3.55 (m, 2H), 3.7 (s, 3H), 5.45-5.55 (m, 2H), 7.35-7.7 (m, 4H)

Example GG-6) The title material from Example GG-5 (8.4g, 18.2mmol) was treated with 125 mL IN hydrochloric acid and the reaction was stiπed for an hour at room temperature. After the reaction mixture had been extracted 2 X 75 mL of ethylacetate the aqueous layer was stripped in vacuo at 56°C to yield 4g ofthe title material (100% crude yield).

^lΪT NMR (CD3OD) : 1.6 (s, 3H), 2.3-2.4 (m, 2H), 2.65-2.8 (m, 2H), 3.6-3.65 (m, 2H), 3.87 (s, 3H), 5.4-5.5 (m, IH), 5.75-5.85 (m, IH)

Example GG-7) The title product of Example GG-6 (1.9g, 8.5 mmol) was dissolved in a mixture of 15mL dioxane and 8mL of water. Solid potassium bicarbonate was then carefully added to avoid foaming. The reaction mixture was stined for 10 min before tertiarybutyloxycarbonyl anhydride was added portion-wise and reaction mixture was stiπed at ambient temperature for 24 hours. The reaction mixture was diluted with 100 mL of ethylacetate and 50 mL of water before it was poured into a separatory funnel. The organic layer was separated, dried (Na₂SO₄), filtered and stripped to yield the title material as a colorless oil (1.9g, 78% crude yield).

^]H NMR (CDCI₃) : 1.42 (s, 9H), 1.55 (s, 3H), 2.3-2.36 (m, 2H), 2.58-2.65 (m, 2H), 3.65- 3.7 (t, 2H), 3.75 (s, 3H), 5.42-5.5 (m, IH), 5.55-5.62 (m, IH)

Example GG-8) Another 1.9 g sample ofthe title material from Example GG-6 was converted by the methods of Example GG-7 to the crude Z / E mixture ofthe title product of Example GG-7. This material further purified on silica with a solvent system of ethylacetate / hexane in a 20/80 ratio to obtain the minor E-isomer as well as the major Z- isomer.

Example GG-9) The title Z-isomer from Example GG-8 (1.8 g, 6.25 mmol) was dissolved in 20mL of acetonitrile and this solution was cooled to 0 °C. Pyridine (0.76g, 9.4mmol) was then added followed by the portion- wise addition of solid dibromotriphenylphosphorane (3.46g, 8.2mmol) over 10 min. The reaction mixture was stiπed under Argon for 24 hours at room temperature. The precipitate that formed was filtered off. The filtrate was concentrated in vacuo to give 2.8 g of an oil that was purified on silica gel using a solvent system of ethylacetate / hexane in a 60/ 40 ratio. The l.lg of title material (50 %) was characterized by NMR.

TI NMR (CDC1₃) : 1.44 (s, 9H), 1.55 (s, 3H), 2.6-2.65 (m, 4H), 3.35-3.4 (m, 2H), 3.75 (s, 3H), 5.4-5.45 (m, IH), 5.55-5.6 (m, IH)

Example GG-10) The title material from Example GG-8 (300mg, 0.86mmol) was dissolved in 25 mL of dimethylformamide (DMF). The potassium salt of 3-methyl- 1,2,4- oxadiazolin-5-one ( 130mg, 0.94mmol) was added and the reaction mixture was heated to 52°C and maintained there for 18 hours with stirring. It was then cooled to room temperature before the DMF was stripped in vacuo at 60°C. The residue was purified on silica gel with a gradient of 60/40 to 90/10 ethyl acetate/ hexane to yield 300 mg (95 %) ofthe title material.

^]H NMR (CD₃OD) : 1.35 (s, 3H), 1.43 (s, 9H), 2.32 (s, 3H), 2.45-2.55 (m, 4H), 3.65-3.7 (m, 2H), 3.72 (t, 3H), 5.5-5.6 (m, 2H)

Example GG-11) The product of Example GG-10 (300mg) was treated with 0.05 N of aqueous HCl and this solution was stiπed for 30 min. The solvent was removed in vacuo to afford the desired material in nearly quantitative yield.

1H NMR (CD₃OD) : 1.6 (s, 3H), 2.25 (s, 3H), 2.45-2.55 (m, 2H), 2.7-2.8 (m, 2H), 3.3- 3.4(m, 5H), 5.5-5.6 (m, IH), 5.7-5.8 (m, IH)

Example GG-12) The title material from Example GG-11 (198 mg, 0.54 mmol) was dissolved in 50 mL of MeOH. Formic acid (40mg) was then added followed by Palladium on Calcium carbonate (400 mg). The reaction mixture was heated to 65 °C with stirring in a sealed tube for 24 hours. It was then cooled to room temperature and filtered. The filtrate was concentrated in vacuo and the residue purified by reverse phase HPLC to yield 115 mg (75%) ofthe title material.

1H NMR (CD₃OD) : 1.4 (s, 3H), 1.95 (s, 3H), 2.25 (s, 3H), 2.4-2.52 (m, 4H), 3.25-3.35 (m, 2H), 3.75 (t, 3H), 5.54-5.62 (m, 2H)

Example GG) The title material (75 mg) from Example GG-12 was dissolved in 15 mL of 2N hydrochloric acid. The reaction mixture was heated to a reflux and stined for 6 hours before ot was cooled to room temperature. The solvent was removed in vacuo. The residue was dissolved in 25 mL of water and stripped on the rotary evaporator to remove excess hydrochloric acid. The residue was dissolved in water and lyophilized to give 76 mg (-100 %) ofthe title material.

Elemental analyses Calcd for C₁₀H₁₉N₃O₂ + 2.2HC1 + 2.2 H₂O: C, 36.06; H, 7.75; N, 12.61. Found for C₁₀H₁₉N₃O₂ + 2.2HC1 + 2.2 H₂O: C, 35.91; H, 7.61; N, 12.31 1H NMR (CD₃OD) : 1.47 (s, 3H), 2.32 (s, 3H), 2.45-2.64 (m, 4H), 2.58-2.65 (m, 2H), 3.65- 3.7 (t, 2H), 5.55-5.65 (m, 2H)

Example HH

.HCl

(2S,5_JE)-2-amino-2-methyl-6-fluoro-7-[(l-iminoethyl)amino]-5-heptenoic acid, dihydrochloride

Example-HH-1) To a cold (-78 °C) solution of triethyl 2-fluorophosphonoacetate (25.4 g, 105 mmol) in 100 mL of THF was added rø-butyl lithium (63 mL of 1.6 M in hexane, 101 mmol). This mixture was stiπed at -78 °C for 20 min producing a bright yellow solution. A solution of crude 3-[(tert-butyldimethylsilyl)oxy]propanal (J. Org. Chem., 1994, 59, 1139- 1148) (20.0 g, 105 mmol) in 120 mL of THF was then added dropwise over ten minutes, and the resulting mixture was stined for 1.5 h at -78 °C, at which time analysis by thin layer chromatography (5% ethyl acetate in hexane) showed that no starting material remained. The reaction was quenched at -78 °C with sat. aqueous NH₄C1 (150 mL). The organic layer was collected, and the aqueous layer was extracted with diethyl ether (300 mL). The combined organics were washed with brine (200 mL), dried over MgSO , filtered and concentrated. The crude material was filtered through a plug of silica gel (150 g) eluting with hexane (2 L) to give 14.38 g (52%) ofthe desired (2E)-5-[[(l,l-dimethylethyl)di-methylsilyl]oxy]-2- fluoro-2-pentenoic acid ethyl ester product as a clear oil. ^JH NMR and ¹⁹F NMR indicated that the isolated product had an approximate E:Z ratio of 95:5.

HRMS calcd. for C₁₃H₂₆FO₃Si: m/z = 277.1635 [M+H]⁺, found: 277.1645.

1H NMR (CDC1₃) 0.06 (s, 6H), 0.94 (s, 9H), 1.38 (t, 3H), 2.74 (m, 2H), 3.70 (m, 2H), 4.31

(q, 2H), 6.0 (dt, vinyl, IH).

¹⁹F NMR (CDCI₃) -129.78 (d, 0.05 F, J= 35 Hz, 5% Z-isomer), -121.65 (d, 0.95 F, J= 23

Hz, 95% E-isomer).

Example-HH-2) To a solution of Example-HH-1 (6.76 g, 24.5 mmol) in 100 L of methanol at room temperature was added solid NaBH₄ (4.2 g, 220 mmol) in 1.4 g portions over three hours. After 3.5 hours water was added (10 mL). Additional solid NaBH₄ (4.2 g, 220 mmol) was added in 1.4 g portions over three hours. The reaction was quenched with 150 mL of sat. aqueous NH₄C1 and extracted with diethyl ether (2 x 250 mL). The organic layers were combined, dried over MgSO , filtered and concentrated. The crude material, 4.81 g of clear oil, was purified by flash column chromatography on silica gel eluting with 10% ethyl acetate in hexane to give 2.39 g (42%) ofthe desired (2E)-5-[[(l,l- dimethylethyl)dimethylsilyl]oxy]-2-fluoro-2-penten-l-ol product as a clear oil, that contained an approximate E:Z ratio of 93:7 by ¹⁹F NMR.

HRMS calcd. for CnH₂₄FO₂Si: m/z = 235.1530 [M+H]⁺, found: 235.1536.

1H NMR (CDC1₃) 0.06 (s, 6H), 0.88 (s, 9H), 2.35 (m, 2H), 3.62 (t, 2H), 4.19 (dd, 2H), 5.2

(dt, vinyl, IH).

¹⁹F NMR (CDC1₃) -120.0 (dt, 0.07F, 7% Z-isomer), -109.82 (q, 0.93 F, J= 21 Hz, 93% E- isomer).

Example-HH-3) To a mixture of Example-HH-2 (2.25 g, 9.58 mmol), polymer-supported friphenylphosphine (3 mmol/g, 1.86 g, 15 mmol) and 3-methyl-l,2,4-oxadiazolin-5-one (1.25 g, 12.5 mmol) in 60 mL of THF was added dropwise diethylazodicarboxylate (2.35 mL, 14.7 mmol). The reaction mixture was stined for 1 h at room temperature, and additional 3- methyl-l,2,4-oxadiazolin-5-one (0.30 g, 3.0 mmol) was added. After 30 minutes, the mixture was filtered through celite, and the filtrate was concentrated. The resulting yellow oil was triturated with diethyl ether (30 mL) and the solid removed by filtration. The filtrate was concenfrated, triturated with hexane (30 mL) and filtered. The filtrates was concentrated to an oil which was purified by flash column chromatography on silica gel eluting with 15% ethyl acetate in hexane to give 1.83 g (60%) ofthe desired 4-[(2E)-5-[[(l,l- dimethylethyl)dimethylsilyl]oxy]-2-fluoro-2-pentenyl]-3-methyl-l,2,4-oxadi-azol-5(4H)-one product as a clear oil, that contained only the desired E-isomer by ¹⁹F NMR.

HRMS calcd. for C₁₄H₂₆FN₂O₃Si: m/z = 317.1697 [M+H]⁺, found: 317.1699.

1H NMR (CDC1₃) 0.04 (s, 6H), 0.85 (s, 9H), 2.28 (s, 3H), 2.37 (m, 2H), 3.64 (t, 2H), 4.32

(d, 2H), 5.4 (dt, vinyl, IH).

¹⁹F NMR (CDC1₃) -110.20 (q, 1 F, J= 21 Hz).

Example-HH-4) A solution of Example-HH-3 (1.83 g, 5.78 mmol) in a mixture of acetic acid (6 L), THF (2 mL) and water (2 mL) was stiπed at room temperature for 2.5 hours. The resulting solution was concentrated in vacuo to an oil which was dissolved in diethyl ether (50 mL). The organic layer was washed with saturated NaHCO₃, and the aqueous layer was extracted with diethyl ether (2 x 50 mL) and ethyl acetate (2 x 50 mL). The combined organic layers were dried (MgSO₄), filtered and evaporated to give 1.15 g (98%) ofthe desired 4-[(2E)-2-fluoro-5-hydroxy-2-pentenyl]-3-methyl-l,2,4-oxadiazol-5(4H)-one product as a clear colorless oil.

HRMS calcd. for C₈H₁₂FN₂O₃: m/z = 203.0832 [M+Hf, found: 203.0822.

1H NMR (CDC1₃) 2.31 ( 3H), 2.4 (m, 2H), 3.66 (t, 2H), 4.37 (d, 2H), 5.42 (dt, vinyl, IH).

¹⁹F NMR (CDCI3) -110.20 (q, 1 F, J= 21 Hz).

Example-HH-5) To a CH₂Cl₂ (2 mL) solution of friphenylphosphine (238 mg, 0.91 mmol) and imidazole (92 mg) at 0 °C was added solid iodine (230 mg, 0.91 mmol), and the mixture was stined for 5 minutes. To the resulting yellow sluny was added a CH₂CI₂ (1.5 mL) solution of Example-HH-4 (0.15 g, 0.74 mmol). The sluπy was allowed to warm to room temperature and stiπed 30 minutes. The reaction mixture was diluted with CH₂C1₂ (10 mL), washed with saturated Na₂S₂O₃ (5 mL) and brine (5 mL), dried (MgSO₄), filtered and evaporated to an oil. Addition of diethyl ether (10 mL) to the oil gave a white precipitate that was removed by filfration and the filtrate was concentrated to an oil. The crude material was purified by flash column chromatography on silica gel eluting with 30% ethyl acetate in hexane to give 0.18 g (78%) ofthe desired 4-[(2E)-2-fluoro-5-iodo-2-ρentenyl]-3-methyl- l,2,4-oxadiazol-5(4H)-one product as a clear oil, which solidified upon standing, mp = 58.1- 58.6 °C.

Anal, calcd. for H₁₀FIN₂O2: C, 30.79; H, 3.23; N, 8.98. Found: C, 30.83; H, 3.11; N, 8.85. HRMS calcd. for C₈HnFIN₂O2: m/z = 330.0115 [M+Hf, found: 330.0104. 1H NMR (CDCI₃) 2.31 (s, 3H), 2.75 (q, 2H), 3.21 (t, 2H), 4.31 (d, 2H), 5.39 (dt, vinyl, IH). ¹⁹F NMR (CDCI₃) -108.21 (q, IF, J= 21 Hz).

Example-HH-6) To a l-methyl-2-pynolidinone (12 mL) solution of (3S, 6R)-6-isopropyl- 3-methyl-5-phenyl-3,6-dihydro-2H-l,4-oxazin-2-one (Synthesis, 1999, 4, 704-717) (1.10 g, 4.76 mmol), Lil (0.63 g, 4.76 mmol) and Example-ΗΗ-5 (0.85 g, 2.72 mmol) in an ice bath was added 2-tert-butylimino-2-diethylamino-l,3-dimethylperhydro-l,3,2-diazaphosphorine (1.38 mL, 4.76 mmol). The yellow solution became orange upon addition ofthe base, and the resulting solution was allowed to stir at room temperature for 1 hour. The reaction mixture was diluted with ethyl acetate (100 mL), washed with water (2 x 30 mL), dried (MgSO ), filtered and evaporated to a yellow oil. The crude material was purified by flash column chromatography on silica gel eluting with 30% ethyl acetate in hexane to give 0.64 g (57%) ofthe desired alkylated product as a clear oil.

1H NMR (C₆D₆) 0.57 (d, 3H), 0.89 (d, 3H), 1.30 (s, 3H), 1.65 (s, 3H), 1.8 (m, 2H), 2.0 (m, 2H), 2.1 (m, IH), 3.22 (m, 2H), 4.88 (dt, vinyl, IH), 5.49 (d, IH), 7.1 (m, 3H), 7.6 (m, 2H). ¹⁹F NMR (CDC1₃) -110.37 (q, 1 F, J= 21 Hz).

Example-HH-7) To amethanol (20 mL) solution of Example-HH-6 (0.13 g, 0.31 mmol) was added Lindlar catalyst (1.0 g). The stined slurry was heated to 60 °C for 1 hour, and additional Lindlar catalyst (0.30 g) was added. The sluπy was stiπed an additional 1 hour at 60 °C, then cooled to room temperature. The catalyst was removed by filtration through celite, and the filtrate was stripped to give 0.58 g (100%) ofthe desired deprotected amidine product as a pale yellow oil.

MS: m/z = 374.2 [M+H]⁺

1H NMR (CD₃OD) 0.77 (d, 3H), 1.07 (d, 3H), 1.58 (s, 3H), 2.02 (s, 3H), 1.8-2.2 (m, 5H),

3.83 (d, 2H), 5.20 (dt, vinyl, IH), 5.69 (d, IH), 7.4 (m, 3H), 7.7 m, 2H)

¹⁹F NMR (CDCI3) -109.4 (m, IF, J= 21 Hz)

Example-HH) A solution ofthe product from Example-HH-7 (0.58 g, 1.54 mmol) in 1.5 N HCl (25 mL) was washed with diethyl ether (2 x 20 mL) and refluxed for 1 hour. The solvent was stripped and the crude amino acid ester was dissolved in 6 N HCl (15 mL) and heated to reflux. After six hours, the solvent was removed in vacuo, and the resulting foam was purified by reverse-phase HPLC eluting with a 30 minute gradient of 0-40% CH₃CN/H₂O(0.25% acetic acid). Fractions containing product were combined and concentrated to a foam. The product was dissolved in 1 N HCl and the solvent removed in vacuo (2x) to give 0.15 g (29%) ofthe desired (2S,5E)-2-amino-2-methyl-6-fluoro-7-[(l- iminoethyl)amino]-5-heptenoic acid, dihydrochloride product.

HRMS calcd. for C₁₀H₁₉FN₃O₂: m/z = 232.1461 [M+H]⁺, found: 232.1485.

1H NMR (D₂O) 1.43 (s, 3H), 2.10 (s, 3H), 1.8-2.1 (m, 4H), 3.98 (d, 2H) 5.29 (dt, vinyl,

IH). ¹⁹F NMR (CDC1₃) -109.97 (q, 1 F, J= 21 Hz).

Example II

(2S,5E)-2-amino-2-methyl-6-fluoro-7-[(l-iminoethyl)amino]-5-heptenoic acid, dihydrochloride

Example-II-1) To a l-methyl-2-pyπolidinone (7500 mL) solution of methyl N-[(3,4- dichlorophenyl)-methylene]-alaninate (748.5 g, 2.88 mol) under nitrogen was added Lil (385.5 g, 2.88 mol) and the resulting sluπy stiπed approximately 20 minutes to give a clear solution. The solid from Example-HH-5 (750 g, 2.40 mol) was then added and the resulting solution cooled in an ice bath to -0 °C. Neat BTPP (900 g, 2.88 mol) was added dropwise over 25 minutes maintaining the internal temperature below 5 °C. After stirring for an additional 1.5 hour at 5 °C, the reaction was determined to be complete by HPLC. At this time, 7500 mL of methyl t-butyl ether (MTBE) was added followed by addition of 9750 mL of a water/crushed ice mixture. The temperature rose to 20 °C during this operation. After stirring vigorously for 5-10 minutes, the layers were separated and the aqueous layer washed with twice with 6000 mL of MTBE. The MTBE layers were combined and washed two times with 7500 mL of water. The resulting MTBE solution was then concentrated to -5000 mL, treated with 11625 mL of 1.0 N HCl, and stiπed vigorously at room temperature for one hour. The layers were separated and the aqueous layer washed with 7500 ml of MTBE. About 1 kg of sodium chloride was added to the aqueous layer and the resulting mixture stirred until all the salt had dissolved. At this point, 7500 mL of ethyl acetate was added, the resulting mixture cooled to 10° C, and 2025 mL of 6.0 N sodium hydroxide added with good agitation. The resulting pH should be about 9. The layers were separated and the aqueous layer was saturated with sodium chloride and extracted again with 7500 mL of ethyl acetate. The combined ethyl acetate extracts were dried (MgSO₄) and concentrated to a light oil. It should be noted that the ethyl acetate was not complete removed. With agitation, 3000 ml of hexane then is added to generate a sluπy that was cooled to 10 °C. The granular solid was collected by filtration and washed with 1500 mL of hexane. About 564 g (82% yield) ofthe desired pure aminoester (>95% pure by HPLC) was obtained as a white solid, m.p. 82.9-83.0 °C. LCMS: m/z = 288.2 [M+H]⁺. Chiral HPLC (Chiralpak-AD normal phase column, 100% acetonitrile, 210 nm, 1 mL/min): Two major peaks at 4.71 and 5.36 min (1:1).

1H NMR (CDC1₃): 1.40 (s, 3H), 1.7-1.8 (m, 2H), 2.0 (br s, 2H), 2.2 (m, 2H), 2.29 (s, 3H), 3.73 (s, 3H), 4.34 (dd, 2H), 5.33 (dt, IH).

Example-II-2) Separation ofthe individual enantiomers ofthe product from Example-II-1 was accomplished on preparative scale using chiral HPLC chromatography (ChiralPak-AD, normal phase column, 100% acetonitrile) to give the desired pure (2S)-2-methyl amino ester product title product. ChiralPak-AD, normal phase column, 100% acetonitrile, 210 nm, 1 mL/min): 5.14 min (99%).

Example-II-3) A slurry ofthe product of Example-II-2 (2.30 g, 8.01 mmol) in 0.993 M NaOH (30.0 ml, 29.79 mmol) was stiπed 2 hours at room temperature. To the resulting clear colorless solution was added 1.023 M HCl (29.10 mL, 29.76 mmol). The resulting clear solution was concentrated until a precipitate began to form (approx. 30 mL). The slurry was warmed to give a clear solution that was allowed to stand at room temperature overnight. The precipitate was isolated by filtration. The solid was washed with cold water (2x10 mL), cold methanol (2x10 mL) and Et₂O (2x20 mL). The white solid was dried in vacuo at 40 °C 4 hours to give 1.04 g (53 %) ofthe desired N-hydroxy illustrated product, mp = 247.2 °C.

Anal, calcd. for C₁₀H₁₈FN₃O₃: C, 48.57; H, 7.34; N, 16.99; CI, 0.0. Found: C, 48.49; H, 7.37;

N, 16.91; CI, 0.0.

HRMS calcd. for C₁₀H₁₉FN₃O₃: m/z = 248.1410 [M+H]⁺, found: 248.1390.

1H NMR (D₂O) 1.35 (s, 3H), 1.81 (s, 3H), 1.7-2.0 (m, 4H), 3.87 (d, 2H) 5.29 (dt, vinyl,

IH). ¹⁹F MR (CDC1₃) -112.51 (q, 1 F, J= 21 Hz).

Example-II-4) To a solution of Example-II-3 in methanol is added Lindlar catalyst. The stiπed slurry is refluxed for 2 hours, then cooled to room temperature. The catalyst is removed by filtration through celite, and the filtrate is stripped. The resulting solid is dissolved in water and concentrated repeatedly from 1.0 N HCl to give the desired (2R,5E)-2- amino-2-methyl-6-fluoro-7-[(l -iminoethyl)amino]-5-heptenoic acid, dihydrochloride product.

Example-II-5) A solution of 73.5 g (0.3 mol) ofthe product from Example-II-2 was dissolved in 300 mL of methanol and added dropwise to a preformed mixture of 13.7 g of Lindlar catalyst and 73.5 g of formic acid (1.53 mol) in 312 mL of methanol while maintaining the reaction temperature between 22 °C and 26 °C. After stirring at room temperature for an additional -15 hrs, the reaction was determined to be complete by F¹⁹ NMR. The resulting reaction mixture was filtered through celite and the celite washed 3 times with 125 mL of methanol. The methanol filtrates were combined and concentrated to generate 115 g of the desired amidine title product as a viscous oil.

MS: m/z = 246 (M+H)⁺.

1H NMR (CD₃OD) l . s „ ^" ~ . m, 4H) 2.3 (s, 3H), 3.9 (s, 3H), 4.2 (d, 2H), 5.4 (dt,vinyl),

8.4 (s, 3H).

F¹⁹NMR (CD₃OD) ^~ϊι . q, J= 21 Hz) -111.7 (q, J=21 Hz).

In order to remove trace levels of lead, the crude product was dissolved in 750 mL of methanol and 150 g of a thiol-based resin (Deloxan THP 11) was added. After stirring 3 hrs at room temperature, the resin was filtered off and washed 2 times with 500 mL methanol. The filtrates were collected and concentrated to 99 g ofthe desired amidine title product as a viscous oil.

Alternatively:

A total of 5.0 g ofthe product from Example-II-2 (0.0174 mole, 1.0 equiv) was mixed with 5.0 g of zinc dust (0.0765 moles, 4.39 equiv) in 40 mL of 1-butanol and 10 mL of acetic acid. After stirring for 5 hrs at 50 °C, LC analyses indicated the reaction to be complete. The solids were readily filtered off. The filtrate, after cooling in ice water to 7 °C, was treated with 30 mL of 6 N NaOH (0.180 moles) in one portion with vigorous stirring. After cooling the reaction mixture from 33 °C to 20 °C, the clear butanol layer was separated off and the aqueous layer extracted again with 40 mL of 1-butanol. The butanol extracts were combined, washed with 30 mL of brine followed by approx 10 mL of 6N HCl. After concentration at 70 °C, a clear glass resulted which was identified as the desired amidine title product.

Example-II) A solution of 99 g ofthe product from Example-II-5 in 6 N HCl was refluxed for 1 hr at which time LC analyses indicated the reaction to be complete. The solvent was removed in vacuo to yield 89.2 g of a glassy oil which was dissolved in a mixture of 1466 mL ethanol and 7.5 ml of deionized water. THF was added to this agitated solution at ambient temperature until the cloud point was reached (5.5 liters). An additional 30 ml of deionized water was added and the solution agitated overnight at room temperature. The resulting slurry was filtered and washed with 200 mL of THF to yield 65 g of a white solid identified as the desired title product.

[ ]_D ²⁵ = +7.2 (c=0.9, H₂O) mp = 126-130° C.

MS: m/z = 232 (M+H)⁺.

Anal. Calcd for C₁₀H₂₂N₃FιO₃Cl₂: C, 37.28; H, 6.88; N, 13.04; CI, 22.01. Found: C, 37.52,

H, 6.84, N, 13.21, CI, 21.81.

1H NMR (D₂O) .~ι . s, 3H), 1.8-2.1 (m, 4H), 1.9 (s,3H), 4.0(d, 2H), 5.3(dt, vinyl, IH).

F¹⁹NMR (D₂O) Ti ~ . q_> J=21 Hz) -112.1 (q, J- 21 Hz).

Example JJ

2HC1 (2R,5E)-2-amino-2-methyl-6-fluoro-7-[(l-iminoethyl)amino]-5-heptenoic acid, dihydrochloride

Example- JJ-1) Separation ofthe individual enantiomers ofthe product from Example-II-1 was accomplished on preparative scale using chiral HPLC chromatography to give the desired pure (2R)-2-methyl amino ester product.

Example- JJ-2) The product from Example-JJ-1 is dissolved in water and acetic acid. Zinc dust is added, and the mixture is heated at 60 °C until HPLC analysis shows that little ofthe starting material remains. The Zn is filtered through celite from the reaction mixture, and the filtrate is concentrated. The crude material is purified by reverse-phase HPLC column chromatography. Fractions containing product are combined and concentrated affording the desired (2R)-2-methyl acetamidine product.

Example- JJ) A solution of Example- JJ-2 in 2.0 N HCl is refluxed for 2 h. The solvent is removed in vacuo. The resulting solid is dissolved in water and concentrated repeatedly from 1.0 N HCl to give the desired (2R,5E)-2-amino-2-methyl-6-fluoro-7-[(l-iminoethyl)amino]- 5-heptenoic acid, dihydrochloride product.

Example KK

2HC1

(2R S,5E)-2-amino-2-methyl-6-fluoro-7-[(l-iminoethyl)amino]-5-heptenoic acid, dihydrochloride

Example-KK-1) To an l-methyl-2-pyπolidinone (5 mL) solution of methyl N-[(4- chlorophenyl)methylene]-glycinate (0.33 g, 1.6 mmol), Lil (0.20 g, 1.0 mmol) and a sample ofthe product of Example-HH-5 (0.30 g, 0.96 mmol) in an ice bath was added 2-tert- butylimino-2-diethylamino-l,3-dimethylperhydro-l,3,2-diazaphosphorine (0.433 mL, 1.5 mmol). The solution was allowed to stir at room temperature for 1.5 hours. The reaction mixture was diluted with ethyl acetate (30 mL), washed with water (2 x 20 mL), dried (MgSO₄), filtered, and evaporated to give the crude desired racemic alkylated imine as a yellow oil.

The crude material was dissolved in ethyl acetate (10 mL) and IN HCl (10 mL) was added. The mixture was stined for 2 hours at room temperature, and the organic layer was separated. The aqueous layer was neutralized with solid NaHCO₃ and extracted with ethyl acetate (2 x 30 mL). The organic layer was dried (MgSO₄), filtered and evaporated to give 0.13 g ofthe desired title racemic amino ester product as a yellow oil. This product was used in the next step without further purification. LCMS: m/z = 288.2 [M+H]⁺.

Example-KK-2) To a CH₂C1₂ (15 mL) solution of Example-KK-1 (1.36 g, 4.98 mmol) was added 4-chlorobenzaldehyde (0.70 g, 5.0 mmol) and MgSO₄ (-5 g). The slurry was stiπed at room temperature for 18 hours. The sluπy was filtered, and the filtrate stripped to give 1.98 g (100 %) ofthe desired title imine product as a pale yellow oil. This product was used in the next step without further purification.

1H NMR (C₆D₆) 1.34 (s, 3H), 2.0 (br m, 4H), 3.32 (s, 3H), 3.42 (m, 2H), 3.83 (t, IH), 4.98 (dt, vinyl, IH).

Example-KK-3) To a CH₂C1₂ (2 mL) solution ofthe product of Example-KK-2 (0.25 g, 0.63 mmol) was added methyl iodide (0.200 mL, 3.23 mmol) and O(9)-allyl-N-(9- anthracenylmethyl)-cinchonidinium bromide (40 mg, 0.066 mmol). The solution was cooled to -78 °C and neat BTPP (0.289 mL, 0.95 mmol) was added. The resulting orange solution was stiπed at -78 °C for 2 hours and allowed to reach -50 °C. After 2 hours at -50 °C, the solution was diluted with CH₂C1₂ (10 m^'L), washed with water (10 mL), dried (MgSO₄), filtered, and evaporated to give the crude desired racemic alkylated imine as a yellow oil.

The crude material was dissolved in ethyl acetate (10 mL) and IN HCl (10 mL) was added. The mixture was stiπed for 1 hour at room temperature, and the organic layer was separated. The aqueous layer was neutralized with solid NaHCO₃ and extracted with ethyl acetate (2 x 30 mL). The organic layer was dried (MgSO₄), filtered and evaporated to give 0.16 g ofthe desired racemic 2-methylamino ester product as a yellow oil. The product was used in the next step without further purification. LCMS: m/z = 288.2 [M+H]⁺.

Example-KK-4) The racemic product from Example-KK-3 is dissolved in water and acetic acid. Zinc dust is added, and the mixture is heated at 60 °C until HPLC analysis shows that little ofthe starting material remains. The Zn dust is filtered through celite from the reaction mixture, and the filtrate is concentrated. The crude material is purified by reverse-phase HPLC column chromatography. Fractions containing product are combined and concentrated affording the desired acetamidine product.

Example-KK) A solution of racemic Example-KK-4 in 2.0 N HCl is refluxed for 1 h. The solvent is removed in vacuo. The resulting solid is dissolved in water and concentrated repeatedly from 1.0 N HCl to give the desired title (2R/S,5E)-2-amino-2-methyl-6-fluoro-7- [(l-iminoethyl)amino]-5-heptenoic acid, dihydrochloride product.

Example LL

(2S,5 )-2-amino-2-methyl-7-[(l-iminoethyl)amino]-5-heptenoic acid, dihydrochloride

4- [(Tetrahy dropyranyl)oxy] butyne

Example LL-1) A mixture of 4-dihydro-2H-pyridine (293.2 g 3.5 mol) and concentrated HCl (1.1 mL) was cooled to 5 °C. While continuing to cool externally, 3-butyn-l-ol (231.5 g, 3.3 mol) was added over a period of 30 minutes allowing the temperature to reach 50 °C. Reaction was held with mixing at room temperature for 2.5 hours before it was diluted with MTBE (1.0 L). The resulting mixture was washed with saturated sodium bicarbonate (2x150 mL). The organic phase was dried over sodium sulfate and concentrated under reduced pressure to afford 500 g (98% crude yield) of product; GC area% of 96%.

5-(Tetrahydro-pyran-2-yloxy)-pent-2-yn-l-ol

Example LL-2) To a solution of the 4-[(tetrahydropyranyl)oxy]butyne product of Example LL-1 (50.0 g, 0.33 mol) in THF (125 mL)' was added a solution of 2N EtMgCl in THF (242 mL, 0.48 mol) under a nitrogen atmosphere over a 30 minute period, allowing the temperature to rise to 48 °C. Mixture was further heated to 66 °C and was held at this temperature for 2 hours before cooling to ambient temperature. Paraformaldehyde (14.5 g, 0.48 mol) was added (small exotherm was observed) and the resulting mixture was heated to 45 °C. After 1 hour of controlling the temperature between 45-55 °C, the mixture turned clear. At this point, the mixture was heated up to 66 °C and stiπed for 2.5 hours. Mixture was cooled to room temperature and saturated ammonium chloride (125 mL) was added slowly over 30 minutes (strong exotheπn was observed) keeping the temperature below 40 °C. The liquid phase was separated by decantation; ethyl acetate (250 mL) and brine (50 mL) were added. The organic phase was separated and washed with brine (2x50 mL) and water (1x50 mL). The organic layer was dried over sodium sulfate and concentrated under reduced pressure to afford 51 g of a lightly yellow colored oil (85% crude yield); GC area% = 88% title product, 6% starting material.

5-(Tetrahydro-pyran-2-yloxy)-pent-2-en-l-ol

Example LL-3) To a 500 mL Pan bottle, under a nitrogen atmosphere, was charged the 5- (tetrahydro-pyran-2-yloxy)-pent-2-yn-l-ol product of Example LL-2 (40.2 g, 0.22 mol), Lindlar catalyst (2.0 g), ethanol (120 mL), hexane (120 mL), and 2,6-lutidine (457 mg). Reaction mixture was purged five times each with nitrogen and hydrogen gas. Parr bottle was pressurized with hydrogen to 5 psi and shaken until 98% ofthe theoretical hydrogen was consumed. Hydrogen was released from the vessel and the reaction was purged with nitrogen five times. Mixture was filtered through a pad of Solka Floe and the catalyst was rinsed with ethanol (2x50 mL). The filtrate and rinses were combined and concentrated under reduced pressure to afford 40.3 g (99% yield) ofthe title material as a yellow colored oil (GC area % = 96%).

3-Methyl-4- [5-(tetr ahy dro-pyran-2-yloxy)-pent-2-enyl] -4H- [1 ,2,4] oxadiazol-5-one

Example LL-4) To a solution ofthe 5-(tetrahydro-pyran-2-yloxy)-pent-2-en-l-ol product of Example LL-3 (11.8 g, 0.063 mol) in toluene (42 mL) was added) triethylamine (6.4 g, 0.063 mol). The mixture was cooled to -5 °C and methanesulfonyl chloride (7.3 g, 0.63 mol) was added via syringe at such rate as to keep the pot temperature below 10 °C. The mixture was allowed to warm to room temperature and stined for two hours. The mixture was filtered by suction and rinsed on the filter with toluene (2x20 mL). The filtrate and washes were added to a mixture ofthe sodium salt of 3-methyl-l,2,4-oxadiazolin-5-one (8.6 g, 0.063 mol) in DMF (10 mL). The mixture was stiπed with a mechanical stiπer and heated at 45 °C for 5 hours. Water (40 mL) was added and the mixture was stiπed for 5 minutes and then the layers were separated. The toluene layer was washed with water (3x20 mL), dried over MgSO₄, and concentrated to afford 16.5 g (97.3%) of an orange colored crude product (area% GC consisted of 71% title product, 18% toluene, and 4% of an impurity).

4-(5-Hydroxy-pent-2-enyl)-3-methyl-4H-[l,2,4]oxadiazol-5-one

Example LL-5) To a solution the 3-methyl-4-[5-(tetrahydro-pyran-2-yloxy)-pent-2-enyl]- 4H-[l,2,4]oxadi-az-ol-5-one product of Example LL-4 (16 g, 0.06 mol) in methanol (48 mL) was added ^-toluenesulfonic acid (0.34 g, 2.0 mmol). The mixture was stiπed at room temperature for four hours. Sodium bicarbonate (0.27 g, 3.0 mmol) was added and the mixture was concentrated on a rotary evaporator. The residue was diluted with saturated NaHCO₃ (20 mL) and the resulting mixture was extracted with ethyl acetate (2x60 mL). Extracts were combined and washed with water (2x25 mL), dried over MgSO₄, and concentrated to afford 8.4 g ofthe crude, orange colored oil title product (area% GC= 80%).

Methanesulfonic acid 5-(3-methyl-5-oxo-[l,2,4]oxadiazol-4-yl)-pent-3-enyl ester

Example LL-6) To a solution of the 4-(5-Hydroxy-pent-2-enyl)-3-methyl-4H- [l,2,4]oxadiazol-5-one product of Example LL-5 (8.27 g, 0.045 mol) in methylene chloride (33 mL) was added triethylamine (5.0 g, 0.49 mol). The mixture was cooled to -5 °C and methanesulfonyl chloride (5.5 g, 0.048 mol) was added at such rate as to keep the temperature below 8 °C. The cooling bath was removed and the mixture was stined for 3 hours as it warmed up to room temperature. Water (15 mL) was added and the mixture was stined for 5 minutes and then the layers were separated. The organic phase was washed with water (10 mL), dried over MgSO₄, and concentrated to give a light amber colored residue. The residue was dissolved in ethyl acetate (8 mL) and kept at 5 °C overnight. Precipitated solids were filtered off by suction and rinsed on the filter with minimum volume of ethyl acetate and then air-dried on the filter to afford 6.8 g (58% yield) ofthe title product.

1H NMR (CDC1₃) δ 5.76 (dtt, J=10.9, 7.5, 1.5 Hz, IH), δ 5.59 (dtt, J=10.9, 7.0, 1.5 Hz, IH),

δ 4.31 (t, J=6.3 Hz, 2H), δ 4.27 (dd, J=7.0, 1.5 Hz, 2H), δ 3.04 (s, 3H), δ 2.67 (q, J=6.7 Hz,

2H), δ 2.28 (s, 3H)

¹³C (CDC1₃) δ 159.0, 156.3, 129.9, 125.1, 68.4, 38.9, 37.2, 27.5, 10.2.

IR cm^"1) 1758, 1605, 1342,1320,1170.

Anal. Calcd. for C₉H₁₄N₂O₅S: C, 41.21; H, 5.38; N, 10.68. Found: C, 41.15; H, 5.41; N, 10.51.

4-(5-Iodo-pent-2-enyl)-3-methyl-4H-[l,2,4]oxadiazol-5-one Example LL-7) To a solution of the methanesulfonic acid 5-(3-methyl-5-oxo- [l,2,4]oxadiazol-4-yl)-pent-3-enyl ester product of Example LL-6 (20.0 g, 0.076 mol) in acetone (160 ml) was added sodium iodide (17.15 g, 0.114 mol). The mixture was heated to reflux and was stined for 3 hours. External heating was stopped and the mixture was held at room temperature overnight. Solids were removed by filfration and rinsed on the filter. The filtrate and washes were combined and concentrated and the heterogeneous residue was extracted with ethyl acetate (120 mL). The organic layer was washed with water (60 mL), 15% aqueous solution of sodium thiosulfate (60 mL) and water (60 mL); dried over MgSO₄ and concentrated under reduced pressure to afford 22.1 g (98% yield) ofthe title oil product.

2-[(3,4-Dichloro-benzylidene)-amino]-propionic acid methyl ester

Example LL-8) To a mechanically stined sluπy of L-alanine methyl ester hydrochloride (200.0 g, 1.43 mol) in methylene chloride (2.1 L) under a nitrogen atmosphere was added triethylamine (199.7 mL, 1.43 mol) over 12 min (during the addition solids partially dissolved and then reprecipitated). After 10 min, 3,4-dichlorobenzaldehyde (227.5 g, 1.30 mol) and magnesium sulfate (173.0 g, 1.43 mol) were added (temperature increased 6 °C over 30 min). After 2.5 h, the mixture was filtered. The filtrate was washed with water (l x l L) and brine (1 x 500 mL), dried over sodium sulfate, filtered and concentrated to give 313.3 g, 92.4% yield of oil product. 1H NMR (400 MHz, CDC13) . 8.25 (s, IH), 7.91 (d, IH), 7.58 (dd, IH), 7.49 (d, IH), 4.17 (t, IH), 3.76 (s, 3H), 1.53 (d, 3H). Anal. Calcd for C_nHπCl₂NO₂: C, 50.79; H, 4.26; CI, 27.26; N, 5.38. Found: C, 50.37; H, 4.10; CI, 26.87; N, 5.38.

Rflc-2-Amino-2-methyl-7-(3-methyl-5-oxo-[l,2,4]oxadiazol-4-yl)-hept-5-enoic acid methyl ester

Example LL-9) Method 1. A solution ofthe product of Example LL-7 (114.2 g, 0.39 mol) and the product of Example LL-8 (151.5 g, 0.58 mol) in dimethylformamide (1.4 L) under nitrogen atmosphere was cooled to -8 °C. Lithium iodide (78.1 g, 0.58 mol) was then added in 3 equal portions over 19 min. The mixture was stiπed for 20 min at -7 °C and then (tert- butylimino)-tris(pyr-rolidino)phosphorane (194.0 mL, 0.62) was added over 36 min (maximum temperature = -2.6 °C). After 10 min, the cooling bath was removed and the solution was stined at ambient temperature for lh. The mixture was then poured into cold water (1.4 L) and extracted with ethyl acetate (2 x 1.0 L). The combined organic layers were washed with water (2 x 400 mL) and brine. The ethyl acetate layer was treated with 1 N HCl (780 mL) and stiπed for 1 h. The aqueous layer was separated and extracted with ethyl acetate (2 x 400 mL) and then neutralized with sodium bicarbonate (110 g). The mixture was extracted with ethyl acetate (1 x 500 mL). The organic layer was dried over sodium sulfate, filtered, concentrated and then treated with methyl t-butyl ether to give a crystalline product: first crop 14.4 g; second crop 6.6g (GC purity = 96.2 and 91.9%, respectively). The aqueous phase was saturated with sodium chloride and extracted with ethyl acetate (4 x 500 mL). The combined organic layers were dried over sodium sulfate, filtered, concentrated and then treated with methyl t-butyl ether to give a crystalline product: first crop 33.4 g; second crop 10.8 g (GC purity = 89.6 and 88.8%, respectively. Total crude yield 65.2 g, 62.4%. Method 2. To a solution ofthe product of Example LL-7 (20.7 g, 0.070 mol) and the product of Example LL-8 (22.9 g, 0.088 mol) in dimethylformamide (207 mL) under a nitrogen atmosphere was added cesium carbonate (29.8 g, 0.092). The mixture was stined at rt for 16 h and then diluted with water (300 mL) and extracted with ethyl acetate (2 x 200 mL). The combined ethyl acetate layers were washed with water (3 x 100 mL) and brine and then treated with 1 N HCl (184 mL). After 1 h, the layers were separated and the aqueous layer was extracted with ethyl acetate (3 x 100 mL) and then neutralized with sodium bicarbonate (15.5 g). The mixture was extracted with ethyl acetate (1 x 150 mL). The aqueous layer was saturated with sodium chloride and extracted with ethyl acetate (3 x 100 mL). The combined organic layers were dried over sodium sulfate, filtered and concenfrated to give a yellow solid, 11.9 g, 62.9%; GC purity = 96.6%. The crude product was recrystalhzed from warm methyl t-butyl ether or ethyl acetate.

1H NMR (400 MHz, CDC1₃) 5.68 (m, IH), 5.36 (m, IH), 4.23 (d, 2H), 3.73 (s, 3H), 2.43 (s, 3H), 2.18 (m, 2H), 1.81 (m, IH), 1.69 (s, br, 2H), 1.66 (m, IH), (1.36, 3H) ¹³C NMR (400 MHz, CDC1₃) 177.60, 159.01, 156.10, 135.12, 121.82, 57.48, 52.29, 40.12, 39.00, 26.62, 22.56, 10.41

R«c-2-Amino-2-methyl-7-(3-methyl-5-oxo-[l,2,4]oxadiazol-4-yl)-hept-5-enoic acid

Example LL-10) The product of Example LL-9 (0.269g, 1 mmol) was dissolved in 5mL 2 N HCl and heated to reflux under argon. After refluxing for 6 hrs followed by stirring at room temperature for 72 hours, an aliquot was removed and checked by 1H NMR. Approximately 6% of unreacted starting ester remained along with the desired product (verified by LC-MS). The aqueous portion was removed in vacuo, leaving 0.38g of a thick, amber oil. After purification via reverse phase chromatography, followed by lyophilization, one obtained 0.23g, 90.2% ofthe title compound as white, non-deliquescent solids.

Anal. Calcd. for CπHι₇N₃O₄.0.77H₂O: C, 49.09; H, 6.94; N, 15.61. Found: C, 48.71; H, 6.94;

N, 15.98

Mass spec: M+l = 256.

(2S,5Z)-2-Amino-2-methyl-7-(3-methyl-5-oxo-[l,2,4]oxadiazol-4-yl)-hept-5-enoic acid methyl ester

Example LL-11) The title compound (827.3g) was separated from its R enantiomer by preparative chiral chromatography using Novaprep 200 instrument with steady state recycling option. The material was dissolved in absolute ethanol at a concentration of 40 mg/ml and loaded on a 50x500 mm prepacked Chiral Technologies stainless steel column. The adsorbent was 20μ ChiralPak AD. The mobile phase was ethanol/triethylamine 100/0.1; the flow rate equaled 125 ml per min. The crude solution (25 mL) was loaded on the column every 12 mins. A steady state recycling technique was used. Solvent was removed using a rotovap. The final product was isolated as gold oil which solidified on standing; 399.0 g (96.4% recovery).

1H (400 MHz, CD₃OD) 5.68 (dtt, IH, J_{o/e ? c}=10.7 Hz), 5.43 (dtt, IH, J_oι_efimc=l0.7 Hz), 4.82 (s, br, 2H), 4.28 (d, 2H, J=5.5 Hz), 3.73 (s, 3H), 2.27 (s, 3H), 2.26 (m, IH), 2.14 (m,lH), 1.82 (ddd, lH, J=13.6,11.3, 5.4 Hz), 1.67 (ddd, 1H, J=13.6, 11.2, 5.5 Hz), 1.34 (s, 3H) ¹³C NMR (400 MHz, CD₃OD) 178.49, 161.13, 158.70, 135.92, 123.47, 58.55, 52.77,

41.38, 39.96, 26.23, 23.47, 10.23

Anal. Calcd for C₁₂H₁₉N₃O₄: C, 53.52; H, 7.11; N, 15.60. Found: C 52.35; H, 7.20; N, 15.60.

.HCl

(2S,5Z)-7-Acetimidoylamino-2-amino-2-methyl-hept-5-enoic acid methyl ester, dihydrochloride hydrate

Example LL-12) To a solution ofthe product of Example LL-11 (114.5 g, 0.425 mol) in methanol (2.4 L) was added the solid dibenzoyl-L-tartaric acid (152.5 g, 0.425 mol) and 88% formic acid (147 mL, 3.428 mol) at ambient temperature. A slurry of Lindlar catalyst, 5 wt% palladium on calcium carbonate poisoned with lead acetate (37.9 g), in methanol (200 mL) was prepared under nitrogen. The solution of starting material was then added at ambient temperature to the light grey catalyst sluny followed by a methanol rinse (200 mL). The heterogeneous reaction mixture was heated at 45 °C for 1 Vi hours. Steady gas evolution was observed starting at about 40 °C, which indicated the ongoing reaction. The mixture was cooled in an ice/water bath and then filtered through a plug of Supercell HyFlo. The yellow solution was concentrated in vacuo to give a viscous oil, which was dissolved and partitioned between 2 N aqueous HCl (2 L) and ethyl acetate (0.8 L). Layers were separated and the aqueous layer was washed once with ethyl acetate (0.8 L). Solvent and volatiles were removed in vacuo at elevated temperatures (= 70 °C). The intermediate product was used in next the step without further purification or characterization. LC-MS [M+H]⁺ = 228.

Example LL) The crude product of Example LL-12 (170 g) was dissolved in 2 N aqueous HCl (1 L). The resulting orange solution was refluxed overnight before it was allowed to cool back to ambient temperature. The reaction mixture was concentrated to about 1/3 of its volume, and the acidic solution was passed through a solid phase extraction cartridge (25 g of C18 silica) to remove color and other impurities. Solvent was removed in vacuo (- 70 °C) to give 208 g of crude product as yellowish gum.

The crude gum (31.3 g) was taken up in water (250 mL) and the material was loaded onto a pretreated ion exchange column packed with the acidic resin Dowex 50WX4-400 (about 600 g). The resin was first washed with water (1 L), then with dilute aqueous HCl (1 L of 10/90 v/v cone. HCl/water). The product was eluted off the resin with higher ion strength aqueous HCl (1.5 L of 20/90 v/v to 25/75 v/v cone. HCl/water). The aqueous solvent was removed in vacuo (= 70 °C), and the gummy residue was taken up in 4 vol% aqueous trifluoroacetic acid (100 mL). The aqueous solvent was removed in vacuo (— 70 °C), and the procedure was repeated once more. The residue was then dried xmder high vacuum to give 32.2 g of gum as the trifluoroacetic acid salt.

Crude (2S,5Z)-7-acetimidoylamino-2-amino-2-methyl-hept-5-enoic acid, ditrifluoroace- tic acid salt hydrate (32.2 g) was purified by reverse-phase preparative chromatography. The crude was dissolved in 0.1% aqueous TFA (50 ml) and loaded onto a 2-inch ID x 1 meter stainless steel column packed with adsorbent (BHK polar W/S, 50 , 1.16 kg). The product was eluted at a flow rate of 120 mL/min with a step gradient from 0.1% aqueous TFA to 25/75/0.1 acetonitrile/water/TFA. The loading ratio was 36:1 w/w silica to sample. Solvent was removed in vacuo, and the material was converted into the HCl salt by repeated rinses with dilute aqueous HCl and solvent removals in vacuo. Drying under high vacuum gave 27.4 g ofthe title dihydrochloride hydrate as yellowish gum.

1H NMR (D₂O, .: 1.48 (s, 3H), 1.8-1.9 (AB, 2H), 2.10 (s, 3H), 2.01/2.12 (AB, 2H), 3.78 (d,

2H), rota ere 3.87 (d, 2H), 5.6/5.5 (dt, 2H, 11 Hz)

¹³C NMR (D₂O) : 18.7, 21.5, 21.6, 36.4, 39.1, 59.8, 122.6, 134.3, 164.5, 173.7

Elemental Anal. Calcd. for C₁₀Hι₉N₃O₂ ^• 2.2HC1 ^• 2 H₂O: C, 36.21; H, 8.33; N, 12.67; CI

23.51. Found: C, 36.03; H, 7.72; N, 12.67; CI, 23.60. Example MM

.HCl

(2R,5-Z)-2-amino-2-methyl-7-[(l-iminoethyl)amino]-5-heptenoic acid, dihydrochloride

The R-enantiomer isolated during the separation described in Example LL-11 (1.13g, 4.2 mmol) was dissolved in 11 mL 25% aqueous acetic acid and heated to 60 °C. Zinc dust (1.10g) was then added in 4 equal portions at 30-minute intervals. After heating for a total of 3 hours, an aliquot was removed and checked by LC-MS, which indicated only a trace of unreacted starting material remaining, along with desired product. The mixture was cooled to room temperature, filtered and stripped in vacuo, leaving 2.31 g of a slushy white solid. The methyl ester was hydrolysed with dilute hot HCl to the title compound. After purification by reverse phase chromatography followed by lyophilization, 0.3 lg ofthe title compound as a glassy solid was obtained.

Anal. Calcd. for Cι₀H₁₉N₃O₂.1.22 HC1.1.15 H₂O: C, 46.13; H, 8.15; N, 15.09; CI, 15.53. Found: C, 46.38; H, 8.51; N, 15.13; CI, 15.80 Mass spec: M+l = 214

c. Biological Data

Some or all ofthe following assays are used to demonstrate the nitric oxide synthase inhibitory activity ofthe invention's compounds as well as demonstrate the useful pharmacological properties. Citrulline Assay for Nitric Oxide Synthase

Nitric oxide synthase (NOS) activity can be measured by monitoring the conversion of L-[2,3-³H]-arginine to L-[2,3-³H]-citrulline (Bredt and Snyder, Proc. Natl. Acad. Sci. U.S. A., 87, 682-685, 1990 and Moore et al, J. Med. Chem., 39, 669-672, 1996). Human inducible NOS (hiNOS), human endothelial constitutive NOS (hecNOS) and human neuronal constitutive NOS (hncNOS) are each cloned from RNA extracted from human tissue. The cDNA for human inducible NOS (hiNOS) is isolated from a λcDNA library made from RNA extracted from a colon sample from a patient with ulcerative colitis. The cDNA for human endothelial constitutive NOS (hecNOS) is isolated from a λcDNA library made from RNA extracted from human umbilical vein endothelial cells (HUNEC) and the cDΝA for human neuronal constitutive ΝOS (hncΝOS) is isolated from a λcDΝA library made from R A extracted from human cerebellum obtained from a cadaver. The recombinant enzymes are expressed in Sf9 insect cells using a baculovirus vector (Rodi et al, in The Biology of Nitric Oxide, Pt. 4: Enzymology, Biochemistry and Immunology; Moncada, S., Feelisch, M., Busse, R., Higgs, E., Eds.; Portland Press Ltd.: London, 1995; pp 447-450). Enzyme activity is isolated from soluble cell extracts and partially purified by DEAE-Sepharose chromatography. To measure NOS activity, 10 μL of enzyme is added to 40 μL of 50 mM Tris (pH 7.6) in the presence or absence of test compounds and the reaction initiated by the addition of 50 μL of a reaction mixture containing 50mM Tris (pH 7.6), 2.0 mg/mL bovine serum albumin, 2.0 mM DTT, 4.0 mM CaCl2, 20 μM FAD, 100 μM tefrahydrobiopterin, 0.4

3 mM NADPH and 60 μM L-arginine containing 0.9 μCi of L-[2,3- H]-arginine. The final concentration of L-arginine in the assay is 30 μM. For hecNOS or hncNOS, calmodulin is included at a final concentration of 40-100 nM. Following incubation at 37°C for 15 minutes, the reaction is terminated by addition of 400 μL of a suspension (1 part resin, 3 parts buffer) of Dowex 50W X-8 cation exchange resin in a stop buffer containing 10 mM EGTA, 100 mM HEPES, pH 5.5 and 1 mM L-citrulline. After mixing the resin is allowed to settle and L-[2,3-³H]-Citrulline formation is determined by counting aliquots ofthe supernatant with a liquid scintillation counter. Results are reported in Table I as the IC50 values of

compounds for hiNOS, hecNOS and hncNOS.

Raw Cell Nitrite Assay

RAW 264.7 cells can be plated to confluency on a 96-well tissue culture plate grown overnight (17h) in the presence of LPS to induce NOS. A row of 3-6 wells can be left untreated and served as controls for subtraction of nonspecific background. The media can be removed from each well and the cells washed twice with Kreb-Ringers-Hepes (25 mM, pH 7.4) with 2 mg/ml glucose. The cells are then placed on ice and incubated with 50 μL of buffer containing L-arginine (30 μM) +/- inhibitors for lh. The assay can be initiated by wanning the plate to 37° C in a water bath for lh. Production of nitrite by intracellular iNOS will be linear with time. To terminate the cellular assay, the plate of cells can be placed on ice and the nitrite-containing buffer removed and analyzed for nitrite using a previously published fluorescent determination for nitrite. (T. P. Misko et al, Analytical Biochemistry,

214, 11-16 (1993).

Human cartilage explant assay

Bone pieces are rinsed twice with Dulbecco's Phosphate Buffered Saline (GibcoBRL) and once with Dulbecco's Modified Eagles Medium (GibcoBRL) and placed into a petri dish with phenol red free Minimum Essential Medium (MEM) (GibcoBRL). Cartilage was cut into small explants of approximately 15-45 mg in weight and one or two explants per well are placed into either 96 or 48 well culture plates with 200-500 μL of culture media per well. The culture media was either a custom modification of Minimum Essential Medium(Eagle) with Earle's salts (GibcoBRL) prepared without L- Arginine, without L-Glutamine and without phenol red or a custom modification of serumless Neuman and Tytell (GibcoBRL) medium prepared without L-arginine, without insulin, without ascorbic acid, without L- glutamine and without phenol red. Both are supplemented before use with 100 μM L- Arginine (Sigma), 2 mM L-glutamine, IX HL-1 supplement (BioWhittaker), 50 mg/ml ascorbic acid (Sigma) and 150 pg/ l recombinant human IL-lβ (RD Systems) to induce nitric oxide synthase. Compounds are then added in 10 μL aliquots and the explants incubated at 37° C with 5% CO₂ for 18-24 hours. The day old supernatant is then discarded and replaced with fresh culture media containing recombinant human IL-lβ and compound and incubated for another 20-24 hours. This supernatant is analyzed for nitrite with a fluorometric assay (Misko et al, Anal. Biochem., 214, 11-16, 1993). All samples are done in quadruplicate. Unstimulated controls are cultured in media in the absence of recombinant human IL-1 β. IC₅Q values (Table I) are determined from plotting the percent inhibition of nitrite production at six different concentrations of inhibitor.

Table I shows examples of biological activity for some ofthe compounds ofthe present invention.

TABLE I Biological Activity: Nalues represent averages across all experiments and all lots studied.

In Vivo Assay

Rats can be treated with an intraperitoneal injection of 1-12.5 mg/kg of endotoxin (LPS) with or without oral administration ofthe nitric oxide synthase inhibitors. Plasma nitrite/nitrate levels can be determined 5 hours post-treatment. The results can be used to show that the administration ofthe nitric oxide synthase inhibitors decreases the rise in plasma nitrite/nitrate levels, a reliable indicator ofthe production of nitric oxide induced by endotoxin. As shown in Table II, Example A ((2S,5E)-2-amino-6-fluoro-7-[(l- iminoethyl)amino]-5-heptenoic acid, dihydrochloride) inhibited the LPS-induced increase in plasma nitrite/nitrate levels with an observed ΕD50 value of <0.1 mg/kg, demonstrating the ability to inhibit inducible nitric oxide synthase activity in vivo.

TABLE II

ED₅₀'s for Compounds Determined in Endotoxin-Treated Rats All compounds admimstered orally unless otherwise noted.

Assay for Time Dependent Inhibition

Compounds are evaluated for time dependent inhibition of human NOS isoforms by preincubation ofthe compound with the enzyme at 37° C in the presence ofthe citrulline enzyme assay components, minus L-arginine, for times ranging from 0-60 minutes. Aliquots (10 μL) are removed at 0, 10 ,21 and 60 minutes and immediately added to a citrulline assay enzyme reaction mixture containing L-[2,3-³H]-arginine and a final L-arginine concentration of 30 μM in a final volume of 100 μL. The reaction is allowed to proceed for 15 minutes at 37° C and terminated by addition of stop buffer and chromatography with Dowex 50W X-8 cation exchange ion exchange resin as described for the citrulline NOS assay. The % inhibition of NOS activity by an inhibitor was taken as the per cent inhibition in activity compared to control enzyme preincubated for the same time in the absence of inhibitor. Data shown in Table III is the % inhibition after 21 and 60 minutes preincubation of inhibitor with enzyme.

TABLE III

Assay of Neuroprotective Effects of Selective iNOS Inhibitors During Retinal Ischemia

Pharmacological protection against nerve cell injury during retinal ischemia is relevant to the treatment of other CNS neurodegenerative conditions. The neuroprotective effects of selective iNOS inhibitors in ischemic retinas are studied in cannulated rat retina. The retinal ganglion cells in both retinas of subject rats are retrogradely labeled with Fluoro- Gold. After labeling, retinal ischemia is induced by cannulating both eyes of the anaesthetized rat and raising the blood pressure in one eye above systolic blood pressure for about 90 minutes. The pressure is then lowered and cannulae are withdrawn. Over the following two weeks, a significant portion of retinal ganglion cells degenerate. Over the two- week post-ischemic event period, a test group of rats receives an iNOS selective inhibitor administered daily in drinking water or food. At various times during the two-week post- ischemic event period, selected rats are sacrificed, their retinas harvested, flat-mounted, and analyzed for ganglion cell loss using fluorescence microscopy. Immiinohistochemistry and' immunoblots are performed on the harvested retinas to analyze ganglion cell loss and to localize inducible nitric oxide synthase.

Assay for Protection by iNOS Selective Inhibitors Against Nitric Oxide-Mediated Neurodestruction in Glaucoma

The inducible form of NOS is present in the optic nerve heads of patients with primary open-angle glaucoma, and may be linked to local damage of retinal ganglion cell axons by nitric oxide (A.H. Neufeld et al., Arch. Ophthalmol. 115:497-503, 1997; A.H. Neufeld, Surv. Ophthalmol. 43 (suppl 1):S129-S135, 1999). Aminoguanidine, an inhibitor of iNOS, has been shown to provide neuroprotection to retinal ganglion cells in a rat model of chronic glaucoma (Neufeld et al., Proc. Natl. Acad. Sci. USA 96:9944-48, 1999). To study the effects of selective blocking of iNOS by the iNOS inhibitory compounds according to the methods ofthe present invention, glaucoma-like conditions are produced in rats as described in Neufeld et al.,1999. Chronic, unilateral moderately elevated intraocular pressure (IOP) mimicking glaucoma is produced in rats by cauterizing three episcleral vessels. Intraocular pressure is increased about two-fold. An experimental group of animals is subjected to oral administration of a selective iNOS inhibitor in drinking water for 6 months. A control group receives fresh drinking water from the same source, on the same schedule as the experimental group. At each bottle refill, total volume consumed is recorded. IOP is monitored monthly. After 6 months of moderately elevated IOP, color photographs are taken of the optic disks of each eye using a fundus camera. One week before sacrifice, retinal ganglion cells are retrogradely labeled using Fluoro-Gold or other suitable retrograde label by bilateral microinjection of the superior colliculi. One week later, animals are then sacrificed, retinas harvested and whole, flat-mounted retinas are assayed for retinal ganglion cell density using fluorescence microscopy. Percentage retinal ganglion cell loss in experimental and control groups is compared, and coπelated with recorded levels of changes in IOP. c. Dosages, Formulations and Routes of Administration

Many ofthe iNOS selective inhibitor compounds useful in the methods ofthe present invention can have at least two asymmetric carbon atoms, and therefore include racemates and stereoisomers, such as diastereomers and enantiomers, in both pure form and in admixture. Such stereoisomers can be prepared using conventional techniques, either by reacting enantiomeric starting materials, or by separating isomers of compounds of the present invention! Isomers may include geometric isomers, for example cis-isomers or trans- isomers across a double bond. All such isomers are contemplated among the compounds useful in the methods of the present invention. The methods also contemplate use of tautomers, salts, solvates and prodrugs of iNOS selective inhibitor compounds.

For the methods of the present invention, suitable routes of administration of the selective iNOS inhibitors include any means that produce contact of these compounds with their site of action in the subject's body, for example in the retina of a mammal such as a human. More specifically, suitable routes of administration include oral, intravenous, subcutaneous, rectal, topical, buccal (i.e. sublingual), intramuscular, and intradermal. In an exemplary embodiment, the selective iNOS inhibitors are orally administered.

For the prophylaxis or treatment of neurodegenerative conditions, including stroke, multiple sclerosis, amyotrophic lateral sclerosis, Alzheimer's disease, cerebral ischemia, and physical trauma, the methods include use of an iNOS selective inhibitor as the compound per se, or as pharamaceutically acceptable salts thereof. The term "pharmaceutically-acceptable salts" embraces salts commonly used to form alkali metal salts and to form addition salts of free acids or free bases. The nature of the salt is not critical, provided that it is pharmaceutically acceptable. Pharmaceutically acceptable salts are particularly useful as products of the methods of the present invention because of their greater aqueous solubility relative to a conesponding parent or neutral compound. Such salts must have a pharmaceutically acceptable anion or cation. Suitable pharmaceutically-acceptable acid addition salts of compounds ofthe present invention may be prepared from inorganic acid or from an organic acid. Examples of such inorganic acids are hydrochloric, hydrobromic, hydroiodic, nitric, carbonic, sulfuric and phosphoric acid. Appropriate organic acids include from aliphatic, cycloaliphatic, aromatic, araliphatic, heterocyclic, carboxylic and sulfonic classes of organic acids, examples of which are formic, acetic, propionic, succinic, glycolic, gluconic, lactic, malic, tartaric, citric, ascorbic, glucoronic, maleic, fumaric, pyruvic, aspartic, glutamic, benzoic, anthranilic, mesylic, salicylic, p-hydroxybenzoic, phenylacetic, mandelic, embonic (pamoic), methanesulfonic, ethylsulfonic, benzenesulfonic, sulfanilic, stearic, cyclohexylaminosulfonic, algenic, galacturonic acid. Suitable pharmaceutically-acceptable base addition salts of compounds of the present invention include metallic salts made from aluminum, calcium, lithium, magnesium, potassium, sodium and zinc or organic salts made from N,N'-dibenzylethyleneldiamine, choline, chloroprocaine, diethanolamine, ethylenediamine, meglumine (N-methylglucamine) and procain. Suitable pharmaceutically acceptable acid addition salts of the compounds of the present invention when possible include those derived from inorganic acids, such as hydrochloric, hydrobromic, hydrofluoric, boric, fluoroboric, phosphoric, metaphosphoric, nitric, carbonic (including carbonate and hydrogen carbonate anions), sulfonic, and sulfuric acids, and organic acids such as acetic, benzenesulfonic, benzoic, citric, ethanesulfonic, fumaric, gluconic, glycolic, isothionic, lactic, lactobionic, maleic, malic, methanesulfonic, trifluoromethanesulfonic, succinic, toluenesulfonic, tartaric, and trifluoroacetic acids. The chloride salt is particularly prefened for medical purposes. Suitable pharmaceutically acceptable base salts include ammonium salts, alkali metal salts such as sodium and potassium salts, and alkaline earth salts such as magnesium and calcium salts. All of these salts may be prepared by conventional means from the conesponding conjugate base or conjugate acid of the compounds of the present invention by reacting, respectively, the appropriate acid or base with the conjugate base or conjugate acid ofthe compound.

In one embodiment, the iNOS selective inhibitors useful in the methods ofthe present invention are presented with an acceptable carrier in the form of a pharmaceutical combination. The carrier must be acceptable in the sense of being compatible with the other ingredients of the pharmaceutical combination and must not be deleterious to the subject. Suitable forms for the carrier include solid or liquid or both, and in an exemplary embodiment the carrier is formulated with the therapeutic compound as a unit-dose combination, for example as a tablet that contains from about 0.05% to about 95% by weight of the active compound. In alternative embodiments, other pharmacologically active substances are also present, including other compounds of the present invention. The pharmaceutical compounds of the present invention are prepared by any of the well-known techniques of pharmacy, consisting essentially of admixing the ingredients.

Prefened unit dosage formulations are those containing an effective dose, as herein below described, or an appropriate fraction thereof, of one or more of the therapeutic compounds ofthe combinations.

In general, a total daily dose of an iNOS selective inhibitor is in the range of about 0.001 mg/kg body weight/day to about 2500 mg/kg body weight/day. The dose range for adult humans is generally from about 0.005 mg to about 10 g per day. Tablets or other forms of presentation provided in discrete units may conveniently contain an amount of a therapeutic compound that is effective at such dosage, or at a multiple of the same. For instance, selective iNOS inhibitory compounds used in the present invention can be presented in units containing 5 mg to 500 mg, and typically around 10 mg to about 200 mg.

In the case of pharmaceutically acceptable salts of the therapeutic compounds, the weights indicated above refer to the weight of the acid equivalent or the base equivalent of the therapeutic compound derived from the salt.

For the methods herein described, it should be understood that the amoxmt of a selective iNOS inhibitory compound that is required to achieve the desired biological effect depends on a number of factors, including the specific individual compound or compounds chosen, the specific use, the route of administration, the clinical condition ofthe subject, and the age, weight, gender, and diet ofthe subject.

The daily doses described in the preceding paragraphs for the various therapeutic compounds are administered in a single dose, or in proportionate multiple subdoses. Subdoses are admimstered from two to six times per day. In one embodiment, doses are administered in sustained release form effective to obtain the desired biological effect.

Oral delivery according to the methods of the present invention can include formulations, as are well known in the art, to provide prolonged or sustained delivery of the drug to the gastrointestinal tract by any number of mechanisms. These include, but are not limited to, pH sensitive release from the dosage form based on the changing pH of the small intestine, slow erosion of a tablet or capsule, retention in the stomach based on physical properties of the formulation, bioadhesion of the dosage form to the mucosal lining of the intestinal tract, or enzymatic release ofthe active drug from the dosage form.

Oral delivery according to the methods ofthe present invention can be achieved using a solid, semi-solid or liquid dosage form. Suitable semi-solid and liquid forms include, for example, a syrup or liquid contained in a gel capsule.

To practice the methods of the present invention, pharmaceutical compositions suitable for oral administration can be presented in discrete units, such as capsules, cachets, lozenges, or tablets, each containing a predetermined amount of at least one ofthe therapeutic compounds useful in the methods of the present invention; as a powder or in granules; as a solution or a suspension in an aqueous or non-aqueous liquid; or as an oil-in-water or water- in-oil emulsion.

d. Examples of Embodiments

The following non-limiting examples serve to illustrate various pharmaceutical compositions suitable for practicing the treatment methods ofthe present mvention.

EXAMPLE 1 Pharmaceutical Compositions

100 mg tablets of the composition set forth in Table IV can be prepared for oral administration using wet granulation techniques:

Table IV

EXAMPLE 2 Pharmaceutical Compositions

100 mg tablets of the composition set forth in Table V can be prepared using direct compression techniques:

Table V

The examples described herein can be performed by substituting the generically or specifically described therapeutic compounds or inert ingredients for those used in the preceding examples.

The explanations and illustrations presented herein are intended to acquaint others skilled in the art with the invention, its principles, and its practical application. Those skilled in the art may adapt and apply the mvention in its numerous forms, as may be best suited to the requirements of a particular use. Accordingly, the specific embodiments of the present invention as set forth are not intended as being exhaustive or limiting ofthe invention.

Claims

WHAT IS CLAIMED IS:

1. A method for treating or preventing a neurodegenerative condition in a subject in need of such treatment or prevention, said method comprising administering to the subject a neuroprotective effective amount of an inducible nitric oxide synthase selective inhibitor or pharmaceutically acceptable salt thereof or prodrug thereof, wherein the inducible nitric oxide synthase inhibitor is selected from the group consisting of: a compound having Formula I

I

or a pharmaceutically acceptable salt thereof, wherein:

R¹ is selected from the group consisting of H, halo and alkyl which maybe optionally substituted by one or more halo;

R² is selected from the group consisting of H, halo and alkyl which maybe optionally substituted by one or more halo; with the proviso that at least one of R¹ or R² contains a halo;

R⁷ is selected from the group consisting of H and hydroxy;

J is selected from the group consisting of hydroxy, alkoxy, and NR³R⁴ wherein;

R³ is selected from the group consisting of H, lower alkyl, lower alkylenyl and lower alkynyl;

R⁴ is selected from the group consisting of H, and a heterocyclic ring in which at least one member ofthe ring is carbon and in which 1 to about 4 heteroatoms are independently selected from oxygen, nitrogen and sulfur and said heterocyclic ring may be optionally substituted with heteroarylamino, N-aryl-N-alkylamino, N-heteroarylamino-N-alkylamino, haloalkylthio, alkanoyloxy, alkoxy, heteroaralkoxy, cycloalkoxy, cycloalkenyloxy, hydroxy, amino, thio, nitro, lower alkylamino, alkylthio, alkylthioalkyl, arylamino, aralkylamino, arylthio, alkylsulfinyl, alkylsulfonyl, alkylsulfonamido, alkylaminosulfonyl, amidosulfonyl, monoalkyl amidosulfonyl, dialkyl amidosulfonyl, monoarylamidosulfonyl, arylsulfonamido, diarylamidosulfonyl, monoalkyl monoaryl amidosulfonyl, arylsulfinyl, arylsulfonyl, heteroarylthio, heteroarylsulfinyl, heteroarylsulfonyl, alkanoyl, alkenoyl, aroyl, heteroaroyl, aralkanoyl, heteroaralkanoyl, haloalkanoyl, alkyl, alkenyl, alkynyl, alkylenedioxy, haloalkylenedioxy, cycloalkyl, cycloalkenyl, lower cycloalkylalkyl, lower cycloalkenylalkyl, halo, haloalkyl, haloalkoxy, hydroxyhaloalkyl, hydroxyaralkyl, hydroxyalkyl, hydoxyheteroaralkyl, haloalkoxyalkyl, aryl, aralkyl, aryloxy, aralkoxy, aryloxyalkyl, saturated heterocyclyl, partially saturated heterocyclyl, heteroaryl, heteroaryloxy, heteroaryloxyalkyl, arylalkyl, heteroarylalkyl, arylalkenyl, heteroarylalkenyl, cyanoalkyl, dicyanoalkyl, carboxamidoalkyl, dicarboxamidoalkyl, cyanocarboalkoxyalkyl, carboalkoxyalkyl, dicarboalkoxyalkyl, cyanocycloalkyl, dicyanocycloalkyl, carboxamidocycloalkyl, dicarboxamidocycloalkyl, carboalkoxycyanocycloalkyl, carboalkoxycycloalkyl, dicarboalkoxycycloalkyl, formylalkyl, acylalkyl, dialkoxyphosphonoalkyl, diaralkoxyphosphonoalkyl, phosphonoalkyl, dialkoxyphosphonoalkoxy, diaralkoxyphosphonoalkoxy, phosphonoalkoxy, dialkoxyphosphonoalkylamino, diaralkoxyphosphonoalkylamino, phosphonoalkylamino, dialkoxyphosphonoalkyl, diaralkoxyphosphonoalkyl, guanidino, amidino, and acylamino;

a compound having a structure conesponding to Formula II

or a pharmaceutically acceptable salt thereof, wherein X is selected from the group consisting of -S-, -S(O)-, and -S(O)2-. Preferably, X is -S-. R¹² is selected from the group consisting of Cχ-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C1-C5 alkoxy-Ci alkyl, and C1-C5 alkylthio-Ci alkyl wherein each of these groups is optionally substituted by one or more substituent selected from the group consisting of -OH, alkoxy, and halogen. Preferably, R¹² is Ci-Cg alkyl optionally substituted with a substituent selected from the group consisting of

-OH, alkoxy, and halogen. With respect to R¹³ and R¹⁸, R¹⁸ is selected from the group consisting of -OR and -N(R )(R ), and R is selected from the group consisting of -H, - OH, -C(O)-R²⁷, -C(O)-O-R²⁸, and -C(O)-S-R²⁹; orR¹⁸ is -N(R³⁰)-, and R¹³ is -C(O)-, wherein R and R together with the atoms to which they are attached form a ring; or R is -O-, and R¹³ is -C(R³¹)(R³²)-, wherein R¹⁸ and R¹³ together with the atoms to which they are attached form a ring. If R¹³ is -C(R3²¹)(R³²)-, then R¹⁴ is -C(O)-O-R³³; otherwise R¹⁴ is -H. R¹¹, R¹⁵,

R¹⁶, and R¹⁷ independently are selected from the group consisting of -H, halogen, Ci-Cg alkyl, C2-Cg alkenyl, C2-C6 alkynyl, and C1-C5 alkoxy-Cχ alkyl. R¹⁹ and R²⁰ independently are selected from the group consisting of -H, Cχ-C6 alkyl, C2-C6 alkenyl, C2-Cg alkynyl, and

C1-C5 alkoxy-Ci alkyl. With respect to R²¹ and R²², R²¹ is selected from the group consisting of -H, -OH, -C(O)-O-R³⁴, and -C(O)-S-R³⁵, and R²² is selected from the group consisting of -H, -OH, -C(O)-O-R³⁶, and -C(O)-S-R³⁷; or R²¹ is -O-, and R²² is -C(O)-, wherein R and R together with the atoms to which they are attached form a ring; or R is -C(O)-, and R is -O-, wherein R and R together with the atoms to which they are attached form a ring. R²³ is Ci alkyl. R²⁴ is selected from the group consisting of -H and Ci-

Cg alkyl, wherein when R²⁴ is Ci-Cβ alkyl, R²⁴ is optionally substituted by one or more moieties selected from the group consisting of cycloalkyl, heterocyclyl, aryl, and heteroaryl. With respect to R²⁵ and R²⁶, R²⁵ is selected from the group consisting of -H, alkyl, and alkoxy, and R²⁶ is selected from the group consisting of -H, -OH, alkyl, alkoxy, -C(O)-R³⁸, -C(O)-O-R³⁹, and -C(O)-S-R⁴⁰; wherein when R²⁵ and R²⁶ independently are alkyl or alkoxy, R²⁵ and R²⁶ independently are optionally substituted with one or more moieties selected from the group consisting of cycloalkyl, heterocyclyl, aryl, and heteroaryl; or R²⁵ is -H; and R²⁶ is

97 R selected from the group consisting of cycloalkyl, heterocyclyl, aryl, and heteroaryl. R , R ,

R >29^y, R ,3^j0^υ, - Rr>3^J1ⁱ, r R>3^J2, R --r..33 τ

R>3"₅, τ R,3^J6^D, R ,3"7, R 3^J8^iS, R τ>3^j9^y, and R j4^w0 i.ndependently are selected from the group consisting of -H and alkyl, wherein alkyl is optionally substituted by one or more moieties selected from the group consisting of cycloalkyl, heterocyclyl, aryl, and heteroaryl.

When any of R¹¹, R , 1¹2, R^l\ R^l\ R^1J, R¹⁰, R¹ ', R^lδ, R19^y, R ^υ, R^ZI, R , R ^J, R ", R , R^zo, R ^/, R²⁸, R²⁹, R³⁰, R³¹, R³², R³³, R³⁴, R³⁵ R³⁶, R³⁷, R³⁸, R³⁹, and R⁴⁰ independently is a moiety selected from the group consisting of alkyl, alkenyl, alkynyl, alkoxy, alkylthio, cycloalkyl, heterocyclyl, aryl, and heteroaryl, then the moiety is optionally substituted by one or more substituent selected from the group consisting of -OH, alkoxy, and halogen; a compound is represented by Formula III

or a pharmaceutically acceptable salt thereof, wherein:

R ,41 is H or methyl; and

R ,42 is H or methyl; a compound of formula IV

IV or a pharmaceutically acceptable salt thereof; a compound of Formula V:

or a pharmaceutically acceptable salt thereof, wherein:

R⁴³ is selected from the group consisting of hydrogen, halo, C₁-C₅ alkyl and d-C alkyl substituted by alkoxy or one or more halo;

R⁴⁴ is selected from the group consisting of hydrogen, halo, d-C₅ alkyl and d-C₅ alkyl substituted by alkoxy or one or more halo;

R⁴⁵ is -d alkyl or d-C₅ alkyl be substituted by alkoxy or one or more halo; a compound of Formula VI:

VI or a pharmaceutically acceptable salt thereof, wherein: R R⁴⁴⁶⁶ iiss dd--CC₅₅ aallkkyyll,, ssaaiidd dd--CC₅₅ aallkkyyll ooppttiioonnaallly substituted by halo or alkoxy, said alkoxy optionally substituted by one or more halo; A compound of Formula VII

VII or a pharmaceutically acceptable salt thereof, wherein:

R⁴⁷ is selected from the group consisting of hydrogen, halo, d-C₅ alkyl and d-C₅ alkyl substituted by alkoxy or one or more halo;

R⁴⁸ is selected from the group consisting of hydrogen, halo, d-C₅ alkyl and -d alkyl substituted by alkoxy or one or more halo;

R⁴⁹ is d-C₅ alkyl or d-d alkyl be substituted by alkoxy or one or more halo; a compound of Formula VIII

VIII or a pharmaceutically acceptable salt thereof, wherein:

R⁵⁰ is d-d alkyl, said d-d alkyl optionally substituted by halo or alkoxy, said alkoxy optionally substituted by one or more halo; a compound of formula IX

IX or a pharmaceutically acceptable salt thereof, wherein:

R⁵⁰ is selected from the group consisting of hydrogen, halo, and d-d alkyl, said d- d alkyl optionally substituted by halo or alkoxy, said alkoxy optionally substituted by one or more halo;

R⁵¹ is selected from the group consisting of hydrogen, halo, and d-d alkyl, said d- d alkyl optionally substituted by halo or alkoxy, said alkoxy optionally substituted by one or more halo;

R⁵² is -d alkyl, said d-d alkyl optionally substituted by halo or alkoxy, said alkoxy optionally substituted by one or more halo;

R is selected from the group consisting of hydrogen, halo, andd-d alkyl, said d- d alkyl optionally substituted by halo or alkoxy, said alkoxy optionally substituted by one or more halo; and

R⁵⁴is selected from the group consisting of halo and d-d alkyl, said d-d alkyl optionally substituted by halo or alkoxy, said alkoxy optionally substituted by one or more halo; and

a compound of formula X

or a pharmaceutically acceptable salt thereof, wherein:

R R⁵⁵⁵⁵ iiss dd--dd aallkkyyll,, ssaaiidd dd--dd aallkkyyll ooppttiioonnaally substituted by halo or alkoxy, said alkoxy optionally substituted by one or more halo

2. The method of claim 1 wherein said neurodegenerative condition is stroke.

3. The method of claim 1 wherein said neurodegenerative condition is multiple sclerosis.

4. The method of claim 1 wherein said neurodegenerative condition amyotrophic lateral sclerosis.

5. The method of claim 1 wherein said neurodegenerative condition is Alzheimer's disease.

6. The method of claim 1 wherein said neurodegenerative condition is cerebral ischemia.

7. The method of claim 1 wherein said neurodegenerative condition is focal cerebral ischemia.

8. The method of claim 1 wherein said neurodegenerative condition is physical trauma.

9. The method of claim 1 wherein said neurodegenerative condition is epilepsy.

10. The method of claim 1 wherein said neurodegenerative condition is dementia of acquired immune deficiency syndrome.