NO172495B - PROCEDURE FOR THE PREPARATION OF THERAPEUTIC ACTIVE, NON-Saturated AMINO ACID COMPOUNDS - Google Patents

Description

The present invention relates to a method for the production of therapeutically active, unsaturated amino acid compounds with the formula:

there

R-L means hydrogen, C 1-6 alkyl or hydroxy,

R 2 means hydrogen, C 1-6 alkyl, phenyl-C 1-6 alkyl, halogen or phenyl,

R3 means hydrogen or C1-4-alkyl,

R 4 means hydrogen or C 4 -alkyl,

R 5 means carboxy or C 1-4 alkoxycarbonyl,

R^ means an unsubstituted amino group,

A means an unsubstituted or a C1-4-alkyl-substituted a,C1)-C1-3 alkylene residue or a direct bond and

B means the methylene or a direct bond,

provided that A means an optionally substituted C1-4-alkylene residue, C1-3-alkylene residue when B means a direct bond,

and salts thereof.

The compounds of formula I contain at least one chiral center and can exist as enantiomers or as enantiomer mixtures, further as racemates, if they exhibit more than one chiral center, also as diastereomers or as diastereomer mixtures. The carbon-carbon double bond in the compounds produced according to the invention is, in the case of R2 and R3, respectively in the case of A and B, trans-configured, that is to say, in the case of compounds of formula I, these are compounds of the E series.

Compounds of formula I in which R^ means hydrogen are sub-phosphonic acids those in which R^ means alkyl are phosphinic acids and those in which

Ri means hydroxy, are phosphonic acids. As prefixes to the designation of the compounds of formula I, which can be regarded as substituted carboxylic acids, "phosphino" (R^ means hydrogen), "phosphonyl" (R^ means alkyl) and "phosphono" (R^ means hydroxy) are used.

The a,a)-alkylene with 1 to 3 carbon atoms is methylene, 1,2-ethylene or 1,3-propylene. the a,o)-alkylene which is substituted by alkyl,

is substituted in an arbitrary position. Thus, methylene substituted with alkyl, for example 1,1-ethylene, 1,1-butylene or 1,1-octylene, means 1,2-ethylene substituted with alkyl, for example 1,2-propylene, 1,2-butylene, 2,3-butylene, 1,2-pentylene or 1,2-nonylene, and

1,3-propylene which is substituted with alkyl, for example; 1,3-butylene, 1,3-pentylene or 1,3-decylene.

C1_g-alkyl means, for example, C1_4~alkyl such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or tert-butyl, but

can also mean C5_g-alkyl such as n-pentyl, n-hexyl, n-heptyl or n-octyl, is however preferably methyl.

Phenyl-C1-4 primarily means unsubstituted phenyl-C1-4-alkyl such as benzyl or 1- or 2-phenylethyl.

; C1-6-Alkoxy primarily means C1-4-Alkoxy such as methoxy,

ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy or tert-butoxy.

Halogen preferably has an atomic number of up to 35 and is particularly chlorine, further fluorine or bromine, but can also be iodine.

Salts of compounds produced according to the invention are primarily pharmaceutically usable, non-toxic salts

of compounds of formula I. Such salts are formed for ; example of the carboxy group which is present in compounds of formula I and is primarily metal or ammonium salts, such as alkali metal and alkaline earth metal, for example sodium, potassium, magnesium or calcium salts, as well as ammonium salts with ammonia or suitable, organic amines, such as lower alkylamines, for example methylamine, diethylamine or triethylamine, hydroxyl lower alkylamines, for example 2-hydroxyethylamine, bis-(2-hydroxyethyl)amine, tris-(hydroxymethyl)methylamine or tris-(2-hydroxyethyl)amine, basic aliphatic esters of carboxylic acids, for example 4-aminobenzoic acid-2-diethylaminoethyl ester, lower alkylene amines, for example 1-ethylpiperidine, lower alkylenediamines, for example ethylenediamine, cycloalkylamines, for example dicyclohexylamine, or benzylamines, for example N,N'-dibenzylethylenediamine, benzyltrimethylammonium hydroxide, dibenzylamine or N-benzyl-p<->phenylethylamine.

Compounds of formula I with a primary or secondary amino group can also form acid addition salts, for example with preferably pharmaceutically acceptable, inorganic acids, such as hydrohalic acids, for example hydrochloric or hydrobromic acid, sulfuric acid, nitric acid or phosphoric acid, or with suitable organic carboxylic or sulphonic acids, for example acetic acid, propionic acid, succinic acid, glycolic acid, lactic acid, fumaric acid, maleic acid, tartaric acid, oxalic acid, citric acid, pyruvic acid, benzoic acid, mandelic acid, malic acid, ascorbic acid, pamoic acid, nicotinic acid, methanesulfonic acid, ethanesulfonic acid, hydroxyethanesulfonic acid, benzenesulfonic acid, 4-toluenesulfonic acid or naphthalene sulfonic acid.

Pharmaceutically unsuitable salts can also be used for isolation or purification. For therapeutic use, only the pharmaceutically usable, non-toxic salts are considered, which are therefore preferred.

The compounds produced according to the invention exhibit valuable pharmacological properties. Thus, for example, they are active and selective antagonists of excitatory amino acid receptors that are sensitive to N-methyl-D-aspartic acid (NMDA) in mammals. They are therefore suitable for the treatment of diseases, which depend on a blocking of NMDA-sensitive receptors such as cerebral ischemia, muscle spasms (spasticity), convulsions (epilepsy), anxiety states or manic states.

These beneficial effects can be demonstrated in in vitro or in vivo test devices. Thereby, mammals are preferably used, for example mice, rats or monkeys, or tissues

or enzyme preparations of such mammals. The compounds can be given enterally or parenterally, preferably orally, or subcutaneously, intravenously or intraperitoneally, for example in gelatin capsules or in the form of aqueous suspensions or solutions. The in vivo dose to be used can vary

between 0.1 and 600 mg/kg, preferably between 1 and 300 mg/kg. In vitro, the compounds can be used in the form of aqueous solutions, whereby the concentrations can move between 10~<4> and 1O-** molar solutions.

The inhibitory effect on NMDA-sensitive, excitatory amino acid receptors can be determined in vitro, being measured according to G. Fagg and A. Matus, "Proe. Nat. Acad. Sei.", USA, 81, 6876-80 (1984), in the extent to which the binding of L-<3>H-glutamic acid to NMDA-sensitive receptors is inhibited. In vivo it can

the inhibitory effect is demonstrated on NMDA-sensitive excitatory amino acid receptors, as NMDA-induced convulsions in mice are inhibited.

The anticonvulsant properties of the compounds according to the invention can further be shown by their activity in preventing audiogenically produced seizures in DBA/2 mice (Chapman et al., "Arzneimittel-Forsch.", 34, 1261, 1984).

The anticonvulsant properties can further be demonstrated by

the activity of the compounds according to the invention as electroshock antagonists in mice or rats.

o

A reference to the anxiolytic activity of the compounds according to the present invention gives their good activity in the conflict model according to Cook/Davidson ("Psychopharema-cologia", 15, 159-168 (1968)).

The good activity of the compounds of formula I depends to a surprising extent on the configuration of the double bond. Thus the racemate of it from "Agric. Biol. Chem.", 41 , 573-579 (1979), B.K. Park et al., D-2-amino-5-phosphono-3-cis-pentenoic acid was known by its ability to bind to the NMDA-sensitive receptor to be quite inferior to the racemate of the 2-amino- 5-phosphono-3-trans-pentenoic acid (in the example section these compounds are designated as compounds of the "E series"). Compounds of formula I have been found to be particularly effective, in which the C atom carrying group R 1 has the R configuration.

As mentioned above, the present invention relates to a method for the production of therapeutically active, unsaturated amino acid compounds of formula I and this method is characterized by the fact that in a compound of the formula:

there

Z 1 means C 1-6 -alkyloxy,

Z 2 means a group R 1 or C 1-6 alkoxy,

Z( y means C 1-6 -alkanoylamino or C 1-6 -alkoxycarbonylamino,

and

R 1 , R 2 , R 3 , R 4 , R 5 , A and B have the meaning indicated above, liberates the protective groups Z 5 and optionally Z 1 and/or Z 2 by treatment with a trilower alkylhalosilane and optionally hydrolyzes an obtained ester of formula I where R 5 means C1_4~Alkoxycarbonyl, to the corresponding acid where R5 means carboxy, and/or transfers a free compound to a salt or an obtained salt to the free compound or to another salt.

The group Z5 in the intermediates of formula II are, for example, formyl, acetyl or propionylamino groups, in particular 2-fluoro-, 2-bromo-, 2-iodo-, 2,2,2-trifluoro- or 2,2,2-trichloroacetyl , aroyl, as optionally substituted benzoyl, for example benzoyl, halogenobenzoyl as 4-chlorobenzoyl, lower-alkoxybenzoyl as 4-methoxybenzoyl, or nitrobenzoyl as 4-nitrobenzoyl. Also particularly suitable are lower alkenyloxycarbonyl, for example allyloxycarbonyl, or above all possibly 1- or 2-position substituted lower alkoxycarbonyl such as tert-butoxy, further methoxy or ethoxycarbonylamino groups.

C 1 -C 6 -Alkoxy, and/or Z 2 is, for example, methoxy, ethoxy or isopropyloxy.

The liberation of the protected groups, i.e. of hydroxy from protected hydroxy groups Z^ and/or Z2, of carboxy from protected carboxy groups Z5 and/or of amino which is optionally substituted with lower alkyl or phenyl-lower alkyl, from protected amino groups Z(, takes place by treatment with a tri-C1-g-alkylhalosilane, for example in an inert solvent for example a halogenated, preferably aliphatic hydrocarbon such as in dichloromethane or in other series tri- or tetrachloromethane, trichloroethane or tetrachloroethane, in a temperature range from about -25 to +50°C, preferably from about 0 to about 30°C, for example at temperatures in the range of room temperature, that is at about 15 to about 25°C, advantageously under largely anhydrous conditions and under inert gas, for example under argon or nitrogen.

Processing takes place in a manner known per se, whereby two cleaning operations in particular have proven to be advantageous. Either the crude product can be transferred to a volatile derivative, for example by silylation, and which is thus extracted by distillation, and then desilylated. Or the raw product can be added to an agent that reacts with excess acid, such as hydrohalic acid, and this is then removed. Examples include compounds to which a corresponding acid can be added and lower alkylene oxides (epoxides), such as propylene oxide, can be added.

If compounds of formula I are to be obtained as final substances, where R5 stands for C1-6-Alkoxycarbonyl or carbamoyl, the starting materials of formula II and the process conditions can be chosen such that , Z2 and Z1 are released in the last step, while however the desired group R5 , remains unchanged in this method step.

A particularly preferred embodiment is therefore aimed at the preparation of compounds of formula I, where R 5 means C 1-4 -Alkoxycarbonyl and R 5 amino. According to this embodiment, it is preferably started with compounds of formula II, where Z 1 and Z 2 mean C₁₋ ₂ alkoxy or C₁₋ ₂ alkoxy which is substituted in the position higher than the ot position by halogen, such as chlorine, R 5 stands for C₁ ^-Alkoxycarbonyl and Z5 means lower alkanoylamino such as formylamino, or lower alkoxycarbonylamino such as tert-butyloxycarbonylamino. Starting from such compounds of formula II, the liberation of the protected groups can be carried out in an inert solvent such as a halogenated hydrocarbon, for example dichloromethane, at temperatures close to room temperature, with a reagent such as trimethylsilane, by subsequent treatment with a lower alkanol such as ethanol, and a hydrogen halide - captures as an aliphatic epoxide, in particular an epoxy lower alkane, for example propylene oxide, and is controlled in such a way that compounds of formula I are immediately obtained, where R^ stands for hydroxy, R5 for <C>1-4-alkoxycarbonyl, R^ means amino and the variables R 2 , R 3 and R 4 have the meanings given for formula I.

This method is particularly preferred for the preparation of compounds of formula I, in which A means methylene or 1,3-propylene and B a bond, R 3 and R 4 mean hydrogen and R 2 stands for C 6 -alkyl such as methyl.

Another equally preferred embodiment concerns the preparation of compounds of formula I, where R 5 means carboxy. In this case, it is preferably started with compounds of formula II, where Z 1 and Z 2 mean C 1-6 -alkyloxy or C-1-6-alkyloxy which is substituted in the higher than a position with halogen such as chlorine, R 5 stands for carboxy which is optionally protected, for example, silylated by treatment with N,O-bis-trimethylsilylacetamide, and Z 5 is C 1-6 -alkyloxycarbonylamino, especially α-branched lower alkoxycarbonylamino, such as tert-butyloxycarbonylamino. In this case, the carboxy group is preferably, but not necessarily temporarily, protected, for example by treatment with a silylating agent, such as an N,O-silyl alkanoic acid amide, for example with N,0-trimethyl-silylacetamide.

Intermediate products of formula II are preferably prepared by a compound of formula: where R2, R3, R4, A and B are defined as for formula I, Z^ represents a protected group R^ and X represents reactive, esterified hydroxy, is reacted with a compound with the formula:

where Zi stands for optionally protected hydroxy, Z 2 has the meaning of R^ or stands for protected hydroxy, and R means a preferred group, and can be used without isolation or special purification.

Compounds of formula III can be prepared, for example, by an N-protected aminomalonic acid ester of the formula:

where R5 and Rg mean equally or differently esterified carboxy groups, for example lower alkoxycarbonyl groups, are reacted in a manner known per se with compounds of the formula: where X and X' independently of each other mean reactive, esterified hydroxy as halogen. The thus obtained compounds with the formula:

can be transferred to compounds of formula III, where R4 means hydrogen, as they are saponified and decarboxylated, for example under hydrolytic conditions, which by an acid hydrolysis, for example with halogenated hydrogen acids such as hydrochloric acid, preferably under heating or without prior saponification decarboxycarbonylated by heating in a aqueous, aprotic solvent such as dimethylsulfoxide, in the presence of an alkali halide such as sodium chloride.

According to this, this variant is particularly suitable for the preparation of compounds III, where R4 means hydrogen and Z5 is protected amino such as lower alkanoylamino.

Intermediates III, where A means methylene which is optionally substituted with C^_4~alkyl, B a bond, X halogen and Z^ formylamino, can further be prepared by a compound with the formula:

where D stands for methylidene which is optionally substituted with alkyl, as a corresponding a,e-unsaturated aldehyde, for example acrolein or methacrolein, is reacted with an o-isocyanoacetic acid derivative, as an a-isocyanoacetic acid lower alkyl ester. Under suitable catalysis, such as with low-value metal salts derived from metals of groups I and II of the periodic table, for example corresponding metal oxides or metal halides, such as zinc chloride, cadmium chloride, silver oxide or, preferably, copper oxide or complexes of gold(I) tetrafluoroborate with aliphatic or cycloaliphatic isocyanides, for example bis(cyclohexylisocyanide)gold(I)-tetrafluoroborate, is then obtained in a manner known per se

The 5-vinyl-2-oxazoline-4-carboxylic acid derivative, for example the -ester of the formula: which can be transferred to the open-chain compounds of the formula

where D stands for the methyl group which is optionally substituted with alkyl. These compounds can again be transferred to compounds of formula III by selective halogenation, such as bromination or chlorination, preferably during cooling, during rearrangement of the double bond corresponding to an allyl rearrangement.

Another method for producing compounds II, where R4 stands for hydrogen, Å for methylene or 1,3-propylene and R5 for carboxy, is based on the principle that a compound with the formula:

where Rj^ and Rg mean hydrogen or preferably lower alkyl, such as methyl, and Rc stands for an amino protecting group, is condensed with a 2-R2-acetic acid ester or first with a 1-Rg-ethylene metal compound, for example with isopropenylmagnesium bromide, and then with an acetic acid ester, in the obtained compound of the formula: in which R 5 is C 1-6 -alkoxycarbonyl, this group is reduced, for example with diisobutylaluminum hydride, to hydroxymethyl, the hydroxymethyl group is halogenated, for example brominated with tetrabromomethane/triphenylphosphine, the obtained compound of the formula: where A means the methylene respectively 1 ,3-propylene, X halogen, for example bromine, is further reacted with a compound of formula IV, the oxazolidine ring is cleaved, for example by means of an ion exchanger, such as Amberlyst 15® and in the obtained compound of the formula:

where Zfc means a protected amino group with the formula Rc~NH-(II'), the hydroxymethyl group is oxidized in the usual way to carboxy.

When carrying out the methods described above for the production of the intermediate products III and further conversion of these to the intermediate products II, it is not necessary to isolate all the intermediate steps. Thus, in particular, the transfer of the compounds X to compounds III as well as their further reaction with the compounds IV to intermediates II can preferably be carried out in situ.

A preferred embodiment of the method according to the invention consists similarly in that a compound with the formula: where Rg, R3, R4, R5, A and B are defined as for formula I, Z^ stands for a protected group R5, for example protected amino, and X stands for reactive esterified hydroxy, is reacted with a compound of the formula:

where Zi stands for optionally protected hydroxy, Z2 has the meaning of R^ or stands for protected hydroxy, and R means a preferred group, the protected groups Z^ and optionally Z^ and/or Z2 are released by treatment with a trilower alkylhalosilane, for example with trimethylsilane, and if desired an obtained compound of formula I is transferred to another compound of formula I and/or if desired an obtained compound of formula I is transferred to a salt or an obtained salt to another salt or to a free compound of formula I and/or if desired, an optical isomer is isolated from a mixture of stereoisomeric forms of an obtained compound of formula I or a salt thereof.

A reactive esterified hydroxy group, such as X, is a hydroxy group that is esterified with a strong organic acid, such as one with an aliphatic or aromatic sulfonic acid (such as a lower alkanesulfonic acid, especially methanesulfonic acid, trifluoromethanesulfonic acid, especially benzenesulfonic acid, p-toluenesulfonic acid, p- bromobenzenesulfonic acid and p-nitrobenzenesulfonic acid) or with a strong inorganic acid, such as in particular sulfuric acid, or a halohydrogen acid, such as chlorohydrogen acid or most preferably hydroiodic acid or bromohydrogen acid, esterified hydroxy group.

In this context, reference should be made to the surprising finding that the production of intermediates II and their further conversion according to the invention to the final substances I can be carried out stereoselectively. That is to say, neither in the reaction order III + IV -♦ II, respectively, Ila I, nor in the reaction order X-t III and XI -♦ XII -» XIII XIV -» II does any configuration inversion or significant racemization take place. The process according to the invention is therefore perfectly suitable for the direct preparation of compounds of formula I with the preferred R configuration with the C atom carrying the amino group R . The preparation of sterically uniform compounds of formula I as well as sterically uniform intermediates of formulas II, III, X, XI, XII, XIII and/or XIV is a further object of the present invention.

According to another preferred embodiment, a compound of the formula is subjected to:

selective halogenation, for example using thionyl chloride, to the corresponding intermediate III and this is reacted in situ, i.e. without isolation with the component

IV.

As mentioned, compounds obtained according to the invention can be transferred to other compounds of formula I. In particular, a free amino group Rf can be substituted, for example transferred to an optionally phenylated alkylamino group, free carboxy R5 is esterified or esterified, or amidated carboxy R5 is transferred to free carboxy and /or free or esterified carboxy R5 is converted to amidated carboxy.

For the transfer of an amino group to an optionally phenylated alkylamino group, one alkylates substitutively, for example with a reactive, esterified, optionally phenylated alkanol as an alkyl halide, or reductively, as with an aldehyde or ketone, as well as with catalytically activated hydrogen, or in case of formaldehyde, advantageously with formic acid as reducing agent.

Free carboxylic acids of formula I or their salts can be transferred according to known methods to the corresponding esters with the suitable alcohols or corresponding derivatives thereof, that is to say to the corresponding C 1-6 alkyl esters.

For esterification, a carboxylic acid can be reacted directly with a diazoalkane, especially diazomethane, or with a corresponding alcohol in the presence of a strongly acidic catalyst (for example a hydrohalic acid, sulfuric acid or an organic sulphonic acid) and/or a dehydrating agent (for example dicyclohexylcarbodiimide). Alternatively, the carboxylic acid can be transferred to a reactive derivative, for example a reactive ester, or to a mixed anhydride, for example with an acid halide (for example especially an acid chloride) and this activated intermediate is reacted with the desired alcohol.

Compounds of formula I, where R 5 stands for C 1-6 -alkoxycarbonyl, for example ethoxycarbonyl, can be transferred to compounds of formula I, where R 5 stands for carboxy, for example by hydrolysis especially in the presence of inorganic acids such as halogenated acids or sulfuric acid, or else of aqueous alkalis, such as alkali metal hydroxides, for example of lithium or sodium hydroxide. In this context, it should be noted that the release of carboxy from esterified carboxy can also be carried out in such a way that no significant racemization takes place. This can especially be achieved by treating it with approx. 0.2- to approx. 4-normal, for example approx. 1-normal, i.e. approx. 0.5 to approx. 2-normal, aqueous mineral acid, if necessary during heating, for example to approx. 60°C to approx. boiling temperature, i.e. approximately 100°C. Surprisingly, the saponification, for example of phosphonic acid carboxylic acid lower alkyl esters of formula I, also takes place without the addition of acidic or basic reagents with high yield. A preferred method for producing carboxylic acids of formula I from the corresponding lower alkyl esters, such as the relevant ethyl esters, therefore consists in acid hydrolysis by treatment with approx. 0.2- to approx. 4-normal, aqueous mineral acid, for example hydrochloric acid, sulfuric acid, phosphoric acid or the like, as well as in the - possibly autocatalytic - saponification in water, preferably at elevated temperatures, such as by heating under reflux. The above reactions are carried out according to standard methods in the presence or absence of diluents, preferably those which are inert to the reagents and constitute their solvents, of catalysts, condensation agents or the other agents and/or in an inert atmosphere, at low temperatures, room temperature or elevated temperatures, preferably at the boiling point of the solvent used, at atmospheric or superatmospheric pressure.

The invention further encompasses any variant of the present processes, in which an intermediate product can be obtained and any step of the process is used as the starting material and the remaining steps are carried out, or the process is interrupted at any step thereof or in which the starting materials are formed under the reaction conditions or at which the reaction components are used in the form of their salts or optically pure antipodes. Mainly, in these reactions, such starting materials are to be used, which lead to the formation of the compounds indicated above as particularly valuable.

Depending on the choice of starting materials and methods, the new compounds may exist in the form of one of the possible optical isomers or of their mixtures, for example depending on the number of asymmetric carbon atoms, as pure optical isomers, as antipodes, or as mixtures of optical isomers, such as racemates, or as mixtures of diastereoisomers, from which an antipode can be isolated if desired.

Obtained mixtures of diastereoisomers and mixtures of racemates can, due to the physicochemical differences of the components, be separated into the pure isomers, diastereoisomers or racemates in a known manner, for example by chromatography and/or fractional crystallization.

The obtained racemates (racemic diastereoisomers) can further be separated into the optical antipodes using methods known per se, for example by recrystallization from an optically active solvent, by means of micro-organisms or enzyme catalysts in free or mobilized form or by reacting an acidic end product with an optically active base, which forms salts with the racemic acid, and separating the salts thus obtained, for example on the basis of their different solubilities, into the diastereoisomers, from which the antipodes can be liberated by the action of suitable funds. Basic, racemic products can likewise be separated into the antipodes, for example by separation of their diastereoisomeric salts, for example by fractional crystallization of their d- or 1-tar-trates. Any racemic intermediates or starting materials can be similarly separated.

Finally, the compounds according to the invention are obtained either in free form or in the form of their salts. Any obtained base can be transferred to a corresponding acid addition salt, preferably using a pharmaceutically acceptable acid or an anion exchanger or obtained salts can be transferred to the corresponding free bases, for example using a stronger base such as a metal or ammonium hydroxide or a basic salt, for example an alkali metal hydroxide or carbonate, or a cation exchange preparation. A compound of formula I can also be transferred to the corresponding metal or ammonium salts. These or other salts, for example the picrates, can also be used for purification of the obtained bases. The bases are transferred to the salts, the salts are separated, and the bases are released from the salts. In view of the close relationship between the free compounds and the compounds in the form of their salts, a corresponding salt of this compound is also included whenever a compound is mentioned in the present description, provided that this is possible or meaningful under the given circumstances. The compounds including their salts can also be obtained in the form of their hydrates, or contain other solvents used for the crystallization.

The following examples shall explain the invention and shall not imply any limitation. Temperatures are given in degrees Celsius, and all parts are given in terms of parts by weight. When not otherwise mentioned, all evaporations are carried out under reduced pressure, preferably between approx. 2 and 13 klopascal (kPa).

Example 1: E-2-amino-4-di-5-phosphono-3-pentenesulfuric ethyl ester.

a) 5-(2-propenyl)-oxazoline-4-carboxylic acid ethyl ester (i).

1.6 g of red copper (I) oxide is placed in 200 ml of benzene. Under

intensive stirring, a solution of 140 g of isocyanoacetic acid ethyl ester and 105 g of freshly distilled methacrolein in 200 ml of benzene is added dropwise to this suspension over the course of 10 minutes. The reaction temperature is thereby kept between 30 and 32° under ice cooling. After completion of the dripping, the mixture is kept at 30-32° until the exotherm is complete, and is then stirred for 1 hour at room temperature. After filtering off excess copper (I) oxide, the filtrate is evaporated under vacuum at 30°. The residue is added to 600 ml of ether, filtered over Celite® and evaporated under vacuum to dryness. In this way, 5-(2-propenyl)-2-oxazoline-4-carboxylic acid ethyl ester is obtained as a colorless oil with a boiling point of 110-130° (5.3 Pa). b) E-2-formylamino-3-hydroxy-4-methyl-4-pentenoic acid ethyl ester (2).

139 g of the 5-(2-propenyl)-2-oxazoline-4-carboxylic acid ethyl ester are dissolved in 70 ml of tetrahydrofuran and 27.4 g of water and 3.5 g of triethylamine are added. The reaction mixture is stirred

for 62 hours at 65-70° and taken up after cooling in 200 ml of dichloromethane. The solution is dried over 200 g of magnesium sulphate, filtered and evaporated under vacuum. Purification of the remaining viscous oil by column chromatography (silica gel: hexane:ethyl acetate 3:2) gives the 2-formyl-amino-3-hydroxy-4-methyl-4-pentenoic acid ethyl ester as a mixture of diastereomers, with a melting point of 67°. c) E-2-formylamino-4-methyl-5-diisopropylphosphono-3-pentenoic acid ethyl ester (3).

To a solution of 40.20 g of crude 2-formylamino-3-hydroxy-4-methyl-4-pentenoic acid ethyl ester in 600 ml of 1,2-dichloroethane is added dropwise at 20° under argon to 18.6 ml of thionyl bromide over the course of 5 minutes ( slight cooling). After stirring for 2 hours at room temperature, 400 ml of water is added, whereby the first 50 ml is added slowly. The mixture is stirred well for another 15 minutes. The organic phase is separated and washed three times with ice water and once with ice/saturated potassium bicarbonate solution (pH approx. 7.5). After drying over sodium sulfate and distilling off the 1,2-dichloroethane at 35° in vacuum, the crude bromide is obtained as an intermediate product, to which 160 ml of free isopropyl phosphite is added at room temperature and then stirred at 75° (bath temperature) under partial vacuum (approx. 13 kPa) in 17 hours. Excess triisopropyl phosphite and other volatile by-products are then distilled off under high vacuum (bath temperature 90°). Chromatography of the residue on ten times the amount by weight of silica gel (grain size 0.04-0.06 mm) with ethyl acetate as eluent gives E-2-formylamino-4-methyl-5-diisopropylphosphono-3-pentenoic acid ethyl ester as pale yellow honey ,

IR (CH 2 Cl 2 ): 3410 (NH); 1740 (C0 ester); 1690 (CO amide);

1235 (P=0); 980-1015 (P-0-C).

cx

d) E-2-amino-4-methyl-5-phosphono-3-pentenoic acid ethyl ester (4).

To a solution of 25.42 g of E-2-formylamino-4-methyl-5-diisopropylphosphono-3-pentenoic acid ethyl ester in 102 ml of dry dichloromethane, 56.7 ml of trimethylbromosilane are added dropwise at 20° under argon over the course of 15 minutes. After stirring for 20 hours at room temperature, 102 ml of ethanol is added dropwise over the course of 15 minutes, and the whole is stirred for a further 20 hours. The clear reaction solution is then completely evaporated under vacuum. The residue is evaporated three more times after adding 100 ml of toluene each time. The oily residue is dissolved in 102 ml of ethanol and a solution of 102 ml of propylene oxide in 102 ml of ethanol is added dropwise. The crystalline precipitated product is filtered off after 2 hours (room temperature) and washed with ethanol and ether. After drying (80°, 4 hours) under high vacuum, the analyte E-2-amino-4-methyl-5-phosphono-3-pentenoic acid ethyl ester is obtained, melting point 212° (decomposition).

Example 2: E-2-amino-4-methyl-5-phosphono-3-pentenesulfonyl ester.

a) E-2-formylamino-4-methyl-5-dimethylphosphono-3-pentenoic acid ethyl ester (1).

100.5 g of 2-formylamino-3-hydroxy-4-methyl-4-pentenoic acid ethyl ester is dissolved in 1.5 1 of dichloroethane, added dropwise to 47 ml of thionyl bromide at 20-25° and the mixture is stirred for 1 hour at room temperature. Add 750 ml of water to the reaction mixture and stir it intensively for 10 minutes. The organic phase is separated, extracted with 1 liter of ice water, 1 liter IN potassium hydrogen carbonate solution and again 1 liter of ice water, dried over magnesium sulfate and evaporated. To the E-5-bromo-2-formylamino-4-methyl-3-pentenoic acid ethyl ester thus obtained, a yellow oil, 50 ml of trimethylphosphite is immediately added and the whole is stirred for 15 hours at 70° bath temperature and approx. 15 kPa. The reaction mixture is degassed

for 30 minutes in a water jet vacuum and 1 hour under high vacuum at 40-50°. The product obtained is taken up in 600 ml of water and extracted with 3 x 500 ml of ethyl acetate. The combined organic phases are washed with 2 x 300 ml of water. All aqueous phases are combined, saturated with sodium chloride and extracted with 3 x 500 ml of dichloromethane. The combined organic phases are dried over magnesium sulfate and evaporated. The product is chromatographed over silica gel (ethyl acetate:isopropanol 7:2). In this way, E-2-formylamino-4-methyl-5-dimethylphosphono-3-pentenoic acid ethyl ester is obtained as a yellow oil.

<1->H-NMR (DMSO): 1.82 (d, 3H, 4-CH3); 2.69 (d, 2H);

5.03 (m, 1H); 5.32 (m, 1H).

b) E-2-amino-4-methyl-5-phosphono-3-pentenoic acid ethyl ester (2). 16.9 g of E-2-formylamino-4-methyl-5-dimethylphosphono-3-pentenoic acid ethyl ester are dissolved in 80 ml of dichloromethane under a nitrogen atmosphere and added dropwise at approx. 25° 30 ml of trimethylbromosilane during 30 minutes. The mixture is stirred for 20 hours at room temperature, and then 80 ml of ethanol is added dropwise at approx. 25° during 30 minutes, then stirred for a further 22 hours at room temperature and then evaporated. The residue is dissolved in 80 ml of ethanol, and while cooling slightly, 80 ml of propylene oxide in 80 ml of ethanol is added dropwise. It is stirred for 1 hour at room temperature, filtered and washed with ethanol and ether. E-2-amino-4-methyl-5-phosphono-3-pentenoic acid ethyl ester is obtained in this way, melting point 215-217° (decomposition).

Example 3: E- 2- aml no- 4- me tvi- 5- f osphono- 3- pentenoic acid etvl-ester.

a) E-2-formylamino-4-methyl-5-di(2-chloroethyl)phosphono-3-pentenoic acid ethyl ester (l).

8.2 g of E-5-bromo-2-formylamino-4-methyl-3-pentenoic acid ethyl ester and 19 ml tris-(2-chloroethyl)phosphite are stirred for 20 hours at 70<*> bath temperature. The resulting mixture is chromatographed on silica gel, after which it is eluted with ethyl acetate and ethyl acetate:isopropanol (7:1) and the product is crystallized from ethyl acetate:diethyl ether. E-2-formylamino-4-methyl-5-di(2-chloroethyl)phosphono-3-pentenoic acid ethyl ester is obtained, melting point 47-49".

b) E-2-amino-4-methyl-5-phosphono-3-pentenoic acid ethyl ester (2).

Using 3 g of E-2-formylamino-4-methyl-5-di(chloroethyl)phosphono-3-pentenoic acid ethyl ester is obtained in an analogous manner as in example 2, likewise E-2-amino-4-methyl-5-phosphono- The 3-pentenoic acid ethyl ester, melting point 215° (decomposition).

Example 4: (2R)-2-amino-4-methyl-5-phosphono-3-pentenoic acid.

a) (L)-N-tert-butoxycarbonyl-serine-N-methoxy-N-methylamide (i).

To a solution of 1 kg of (L)-N-tert-butoxycarbonyl-serine in tetrahydrofuran at -20° to -25° is added 541.6 ml of N-methylmorpholine over the course of 27 minutes. After stirring for 15 minutes at the same temperature, 699.6 ml of chloroformic acid isobutyl ester are added over the course of 42 minutes and 445.8 ml of N-methoxy-N-methylamine over the course of 40 minutes. The mixture is allowed to warm to room temperature and the solvent is evaporated on a rotary evaporator. The residue is dissolved in 13 1 of ethyl acetate, the solution is extracted with 3.5 1 of 2N hydrochloric acid and 3 1 of saturated NaHCO 3 solution. The aqueous phases are extracted with 3x11 ethyl acetate, the organic phases are washed with 2 1 of saturated NaCl solution, dried with MgSO 4 and evaporated at 50" under vacuum. The residue is stirred for 2 hours under ice-cooling with 3.5 1 of hexane. The white suspension is filtered and the filtrate is washed with 1 1 of hexane. Drying at 40" in vacuum gave 781 g 1, melting point 116-117".

Elemental analysis for CigB^n^Os:

Calculated: C 48.38*. H 8.12*, N 11.28*;

Found: C 48.28*, H 8.02*, N 11.32*. b) ( L )-3-tert-butoxycarbonyl-2,2-dimethyl-oxazolidine-4-carboxylic acid-N-methoxy-N-methylamide (2).

A mixture of 781 g, 3.3 L of acetone dimethyl acetal and 42 g of pyrldinium-(toluene-4-sulfonate) is heated to 72° and then refluxed for 117 hours. After adding 20 g of pyridinium tosylate, the mixture is boiled for 9 hours, whereby approx. 750 ml of solvent is distilled off and replaced with 750 ml of acetone-dimethyl acetal. The solvent is evaporated and the residue is dissolved in 12 1 diethyl ether. The organic phase is extracted with 2 x 1N hydrochloric acid (1 1, 0.5 1) and once each with saturated NaHCO3 or NaCl solution (each 0.3 1). The aqueous phases are extracted with

2 x 0.5 1 diethyl ether. The rest of the organic phase which is

dried with MgSO4, dissolve hot in 850 ml of hexane:diethyl ether = 9:1. After adding 600 ml of hexane and 50 ml of diethyl ether, the whole is cooled and diluted during crystallization with 1.1 l of hexane. The suspension is filtered. The filter material is washed with hexane. Drying at 40° under vacuum yields 640 g 2 , melting point 67-68°.

Elemental analysis for C13H24N2O5:

Calculated: C 54.15*, H 8.39*, N 9.72*;

Found: C 53.96*, H 8.37*, N 9.91*.

CD

c) (4S)-2,2-dimethyl-4-formyl-3-oxazolidine carboxylic acid tert-butyl ester (3).

c,a) Reduction with LIAIH4.

To a solution of 28.8 g of 2 in 350 ml of dry diethyl ester, 2.53 g of L1A1H4 are added under ice cooling. Internal temperature 5-15°C. After stirring for 1.5 hours at 5°, a solution of 5.77 g of KHSO4 in 60 ml of water is dripped onto such a

way that the temperature does not rise above 15° (40 minutes). , The suspension is filtered and the filter material is washed with ether.

While adding ice, the filtrate is washed with 2 x 200 ml 1N hydrochloric acid, with 2 x 150 ml 5*-lg NaHCO 3 solution and with saturated NaCl solution. The water phases are extracted a

times with diethyl ether, the organic extracts are dried with ; Na2S04 and evaporated. Distillation of the residue at 0.4

mbar gives 17.78 g 3 (boiling point 85-90°C), [a]D = -93' (c=1, CHCl 3 ).

Elemental analysis for C11<H>19NO4:

, Calculated: C 57.63*. H 8.35*. N 6.11*, 0 27.91*;

Found: C 57.59*, H 8.54*, N 6.17*, O 27.74*.

c,b ) Reduction with dilsobutvlalumlnlumhvdrld.

To a solution of 10 g of 2 in 120 ml of dry diethyl ether; 66 ml of a 1M solution of diisobutylaluminium hydride in hexane are dropped under ice-cooling. It is stirred for 10 minutes at room temperature, cooled again to 0° and a solution of 38 g of KHSO4 in 160 ml of water is added

(temp. 0-15°). It is stirred for 30 minutes at room temperature and filtered. The filtrate is washed with diethyl ether and water, the organic phase of the filtrate is washed with 2 x 100 ml IN hydrochloric acid, with 2 x 100 ml 10

*—ig NaHCOs solution and with 2 x 100 ml saturated NaCl solution. The organic extracts are dried with Na2SO4 and evaporated. Distillation of the residue at 0.2 mbar yields 5.3 g 3 (boiling point 78°C). d) 3-((4'R)-N-tert-butyloxycarbonyl-2*,2'-dimethyl-4'-oxa-zolidinyl)-2-methyl-propenoic acid ethyl ester (4).

A solution of 39.5 g of (4S )-2,2-dimethyl-4-formyl-oxazolidine-3-carboxylic acid tert-butyl ester 3 in 200 ml of dichloromethane is added dropwise over the course of 2 hours to a solution of 68.7 g 1 -ethoxycarbonylethylden-triphenylphosphorane in 900 ml of dichloromethane. After stirring for 6 hours at room temperature, it is cooled to 10° and, over the course of 15 minutes, 530 ml of a 10*-ig, aqueous sodium hydrogen phosphate solution is added dropwise. After stirring for 30 minutes at 15°, the organic phase is separated and the aqueous phase is extracted with 250 ml of dichloromethane. The organic phases are dried over magnesium sulfate and evaporated. The residue is stirred out with 70 ml of ether. The suspension is filtered, the filtrate is washed with ether. The filtrate is evaporated, the residue is separated by chromatography on silica gel. Elution with hexane:ethyl acetate = 9:1 gives, in addition to 2.32 g of cis-isomer and 2.21 g of mixed fraction (cis:trans = 38:62), 45.5 g of 4.

1H-NMR (60 MHz, CDCl3, trans-isomer): i.a. 4.7 ppm (m, H-C(4')); 6.7 ppm (d, J=9, H-C(3)).

1H-NMR (60 MHz, CDCl3, cis-isomer): i.a. 5.2 ppm (m, H-C(4')); 6.08 ppm (d, J=7, H-C(3)). e) (4R)-2,2-dimethyl-4-(3'-hydroxy-2*-methyl-prop-1'-enyl)-oxazolidine-3-carboxylic acid tert-butyl ester (5.).

To a solution of 48.7 g of 4 in 1 1 of dry diethyl ether which has been cooled to 3°, 389 ml of a 1-molar solution of diisobutylaluminum hydride in hexane are added over the course of 15 minutes. The mixture is allowed to warm up to 11° and 100 ml of ethyl acetate is added under ice cooling, followed by 50 ml of 2N caustic soda. The mixture is allowed to warm up to approx. 28° without cooling and a further 7 ml of 2N caustic soda is added. The mixture is stirred for 15 hours at room temperature, sodium sulphate is added and filtered. Evaporation of the filtrate yields 42.1 g of crude 5.. A sample (0.97 g) is purified by chromatography on 40 g of silica gel. Elution with hexane:ethyl acetate = 3:1 gives 0.74 g of 2.

<i>H-NMR (300 MHz, DMS0-d6): i.a. 3.52 (dxd, J-9 and 3) and 4.02 (dxd, J-9 and 6), (2H-C(5)); 3.78 (m, 2H-C(3'));

4.54 (m, H-C(4)); 4.81 (t, J-6, 0H); 5.33 (d, J=9, H-C(1')). f) (4R)-2,2-dimethyl-4-(3'-bromo-2*-methyl-prop-1*-enyl)-oxa-zolidin-3-carboxylic acid tert-butyl ester (6).

To a solution of 41.0 g J5 and 60.2 g tetrabromomethane i

1 liter of dry diethyl ether is placed at 0" 47.6 g of triphenylphosphine. After 30 minutes the cooling bath is removed and it is stirred for 17 hours at room temperature. 20 g of tetrabromomethane and 15.9 g of triphenylphosphine are added and stirred for 2 hours at room temperature. The white suspension is filtered

and the filtrate is washed with ether. The evaporation residue from the filtrate is chromatographed on 0.9 kg of silica gel.

Elution with hexane: ethyl acetate = 9:1 gives 30.59 g of 6, melting point 62-65°C.

<1->H-NMR (300 MHz, DMS0-d6): i.a. 3.55 (dxd, J=9 and 2) and ; 4.04 (dxd, J=9 and 6) (2H-C(5)); 4.15 (m, 2H-C(3')), 4.49 (m, H-C(4)); 5.65 (d, J=9, H-C(1')).

g) (4R)-2,2-dimethyl-4-(3'-dimethylphosphono-2'-methyl-prop-1'-enyl)-oxazolidine-3-carboxylic acid tert-butyl ester (7).

in

A solution of 13.4 g of 6 in 70 ml of trimethylphosphite is stirred for 15 hours at 80°. Excess phosphite is evaporated at 24 mbar. Drying the residue in high vacuum gives 14.3 g of crude 7.

<1->H-NMR (300 MHz, DMS0-d6): i.a. 2.63 (d, J<23, 2H-C(3')); 3.59 (d, J=II, (CH3O=2PO).

h) N-((2R )-5-dimethylphosphono-1-hydroxy-4-methyl-3-penten-2-yl)carbamic acid tert-butyl ester (8).

To a solution of 14.0 g of 7 in 250 ml of methanol is added 7 g of Amberlyst®-15 (H+<->form, 20-50 mesh). It is stirred for 17 hours at room temperature, filtered and the filtrate is evaporated. Chromatography of the residue on 0.33 g of silica gel with ethyl acetate: methanol - 10:1 as eluent gives 10.6 g 8.

<1->H-NMR (300 MHz, DMS0-d6): i.a. 4.60 (t, J=6, OH); 6.67 (d, J=7, NH).

i ) ( 2 R )-2-tert-butox y carbonyl amino-5-dimethyl phosphono-4-methyl-3-pentenoic acid ( 9).

i ,a) Oxvdas. lon with chromium sulphide acid.

To a solution of 0.323 g of 8 in 10 ml of acetone is added 0.77 ml of a solution which is 3.25 molar of chromium trioxide and 5.29 molar of sulfuric acid. It is stirred for 40 minutes at room temperature, 2 ml of isopropanol is added followed by 50 ml of ethyl acetate and 0.1 g of activated carbon is added to the mixture. After 10 minutes, the whole is filtered and washed with 50 ml of ethyl acetate. The filtrate is extracted with 3 x 50 ml of 10% lg sodium bicarbonate solution. The water phase is extracted with 2 x 40 ml of ethyl acetate, acidified with 2N hydrochloric acid to pH 1 and extracted with 3 x 70 ml of ethyl acetate. The organic extracts are washed with saturated sodium chloride solution, dried over magnesium sulphate and evaporated. Chromatography on 8 g of silica gel with chloroform: methanol: acetic acid = 18:1:1 as eluent gives 65 mg .9.

1-H NMR (300 MHz, DMSO-d 6 ): 1.37 (s, (CH 3 ) 3 CO ); 1.82

(d, J=2, CH3-C(4)); 2.63 (d, J=22, 2H-C(5)); 3.61 (d, J=II, (CH 3 O) 2 PO); 4.62 (t, J=8, H-C(2)); 5.25 (m, H-C(3)); 7.18 (d, J=8, NH); 11.7-12.5 (CO 2 H).

i ,b ) Oxidase. lon with oxygen/platinum. a

To a solution of 0.66 g of 8 and 0.2 g of sodium hydrogen carbonate in 20 ml of water and 2 ml of dioxane is added a suspension of platinum, prepared by hydration of 313 mg of platinum oxide in 50 ml of water. In a cylindrical apparatus, under vigorous stirring and at 55°, oxygen is passed through the solution by means of a glass frit from below upwards. It is filtered, washed with water and the filtrate is extracted with 5 x 100-150 ml of ethyl acetate. Evaporation of the extracts yields 220 mg of adduct 5. 1 g of Amberlist® 15 (strongly acidic) is added to the water phase, filtered and evaporated under vacuum at 40°. Purification as f,a) gives 156 mg 9.

<1->H-NMR (300 MHz, CDCl 3 ): 1.43 (s, CH 3 ) 3 C); 1.96 (d, J=3, CH 3 -C(4)); 2.55 and 2.71 (2 dxd, J=22 and 15, 2H-C(5)); 3.75 and 3.76 (2d, J=11, 2 0 CH 3 ); 4.97 (m, H-C(2)); 5.25-5.45 (m, NH and H-C(3)).

j) (2R )-2-amino-4-methyl-5-phosphono-3-pentenoic acid (10).

To a solution of 123 mg of 9 in 3 ml of dichloromethane, 0.71 ml of trimethylsilyl bromide is added at 0". After 4 hours of stirring at 0°, 20 ml of water is added. After 30 minutes, the dichloromethane phase is separated and washed with 3 x 15 ml of water. The aqueous phases are extracted with 3 x 20 ml of dichloromethane and evaporated under vacuum. The residue is dissolved in 10 ml of 5N hydrochloric acid and stirred for 48 hours, diluted with 20 ml of water and extracted with 3 x 20 ml of dichloromethane. The water phase is evaporated under vacuum, the residue is dried under high vacuum, dissolve in 3 ml of ethanol and add dropwise approx. 1 ml of propylene oxide. The suspension is filtered. Washing the filtrate with ethanol and drying under high vacuum at room temperature yields 62 mg of 10, melting point 165° (decomposition).

A sample is derivatized to the amide for analysis of enantiomeric unity with (R)-(+)-methoxy-trifluoromethyl-phenylacetic acid chloride. 3 H-NMR analysis (300 MHz) by integration of the 0CH 3 signals gives 2 95* (2R)-isomer (3.44 ppm) and < 5* (2S)-isomer (3.37 ppm).

Example 5: (2R)-2-amino-4-methyl-5-phosphono-3-pentenesulfide ethyl ester♦ a) (4R)-2,2-dimethyl-4-(3'-diisopropylphosphono-2'-methyl- prop-1'-enyl)-oxazolidine-3-carboxylic acid tert-butyl ester ( 1 ).

A solution of 6.68 g of bromide according to example 5f) in 14.8 ml of dry triisopropyl phosphite is heated for 17 hours at a pressure of 100 mbar to 70°C. The mixture is evaporated at 0.4 mbar/70<o>. Chromatography on 350 g of silica gel (eluent, hexane:ethyl acetate = 1:1) gives 8.28 g of 1, Rf value = 0.077. b) N-(( 2R )-5-diisopropylphosphono-1-hydroxy-4-methyl-3-penten-2-yl)carbamic acid tert-butyl ester (2).

To a solution of 4.49 g of phosphonic acid ester in accordance with a) in 100 ml of methanol is added 2.25 g of Amberlyst® 15 (H+<-> form, 20-50 mesh). It is stirred for 2 days at room temperature, filtered and the filtrate is evaporated. Chromatography of the residue on 125 g of silica gel (eluent ethyl acetate:methanol = 20:1) gives 2.44 g of 2.

c ) (2R )-2-tert-butoxycarbonylamino-5-diisopropylphosphono-4-methyl-3-pentenoic acid (3).

To a solution of 1.6 g of alcohol 2 according to b) in 60 ml of acetone is added at 0-5° 3.3 ml of a solution which is 3.25-molar of chromium (VI) oxide and 5.29-molar on sulfuric acid. It is stirred for 6 hours at 0" and 12 hours at room temperature. After adding 5 ml of isopropanol and 40 ml of 20% sodium chloride solution, the whole is stirred for 10 minutes, then continuously for 15 hours in a Kutscher-Steudel apparatus with methyl acetate. The organic phase is dried over sodium sulphate, evaporated and the residue is chromatographed on 75 g of hexane: ethyl acetate acetic acid = 16:10: 1. This gives 0.92 g of 3, [oc]D 94.5° (c=1.2, CHCl3) .

<1->H-NMR (300 MHz, CDCl3): 1.2-1.3 (4d, 2-propO)2); 1.4 (s,

(CH3)3CO). 1.95 (d, J=3, CH 3 -C(4)); 3.5 and 3.62 (2 dxd, J=23 and 15, 2H-C(5)); 4.66 (m, (2-prop0)2); 4.92 (m, H-C(2)); 5.30 (m, H-C(3); 5.42 (d, J-7, NH), 9.0-10.0 (broad, CO2H). d) (2R )-2-tert-butoxycarbonylamino-5 -diisopropylphosphono-4-methyl-3-pentenoic acid ethyl ester (4).

To a solution of 0.2 g of acid 3 according to c) in 15 ml of dry dichloromethane is added at 0-5° 0.09 g of 1-amino-1-chloro-N,N,2-trimethylpropene. After stirring for 30 minutes at 0°, 0.4 g of pyridine in 5 ml of ethanol is added. It is stirred for 90 minutes at 0° and 15 hours at room temperature, diluted with 20 ml of dichloromethane and washed with 2 x 20 ml of water. The organic phase is dried with sodium sulphate, evaporated and chromatographed on 25 g of silica gel. Elution with ethyl acetate:methanol = 10:1 gives 0.12 g 4.

%-NMR (300 MHz, CDCl3): 1.2-1.4 (m, 2 (CH3)2CH0,

(C<H>3)CH2O); 1.45 (s, (C<H>3)3CO); 1.98 (d, J=3, CH 3 -C(4)); 2.55 (d, J=23, 2H-C(5)); 4.2 (m, CH 3 CH 2 O): 4.69 (m, 2 (CH 3 ) 2 CH 0 ); 5.0 (m, H-C(2)); 5.16 (m, H-C(3), NH). e) (2R)-2-amino-4-methyl-5-phosphono-3-pentenoic acid ethyl ester (5.).

To a solution of 0.1 g of ester 4 according to d) in 10 ml

dichloromethane is placed at 0' 0.11 ml of trimethylsilyl bromide. It is stirred for 4 hours at 0° and 15 hours at room temperature. 20 ml of water is added and stirred for 15 minutes, after which the water phase is separated and the water is evaporated under

high vacuum. The residue is dissolved twice in 5 ml of ethanol each time, evaporated and redissolved in 5 ml of ethanol. 0.5 ml of propylene oxide is added. The precipitate is filtered off, washed with ethanol and dried for 15 hours under high vacuum (15 hours); 48 mg 5, [α]n = -75° (c-0.5, H 2 O).

A sample is derivatized for enantiopurity analysis with (R)-(+)-methoxy-trifluoromethyl-phenylacetic acid chloride followed by diazomethane to amide dimethyl ester. ^H-NMR analysis (300 MHz) by integration of the 0CH3~ signals gives > 97* (2R)-isomer (3.5 ppm) and < 3* (2S)-isomer (3.37 ppm).

Example 6: (2R)-2-amino-4-methyl-7-phosphono-3-heptenoic acid.

a) (4R)-2,2-dimethyl-4-(1*-hydroxy-2'-methylprop-2'-enyl)-oxazolidine-3-carboxylic acid tert-butyl ester ( 1 ). To a solution of 6.9 g of (4S)-2,2-dimethyl-4-formyl-oxazolidine-3-carboxylic acid tert-butyl ester (according to example 5c)) in 60 ml of dry tetrahydrofuran is added, over the course of 25 minutes at 0-5°, 45 ml of a 1.1-molar solution of isopropenylmagnesium bromide, dropwise. It is stirred for 45 minutes at 0°, heated to room temperature, cooled again to 10° and 90 ml of buffer solution (l-m, phosphate, pH-7) is added. It is filtered and the filtrate is extracted with 2 x 100 ml of ethyl acetate. The organic phase is washed with 2 x 50 ml of water and with saturated sodium chloride solution, dried with sodium sulphate. Evaporation of the solvent gives 8 g of 1, a mixture of diastereomers. The separation can take place by chromatography on silica gel with hexane:ethyl acetate = 4:1 and crystalline (1'S)-threo-epimer (Rf-value: 0.2) and (1'R)-erythro-epimer (Rf-value: 0.16) in the ratio approx. 1:2. b) (4R)-4-(1'-acetoxy-2'-methyl-prop-2'-enyl)-2,2-dimethyl-oxazolidin-3-carboxylic acid tert-butyl ester (2).

To a solution of 15.6 g of epimer mixture According to a) 1 60 ml of pyrldln are added dropwise at 0-5° during 10 minutes 60 ml of acetic anhydride. It is stirred for 15 hours at room temperature, diluted with 0.5 liters of diethyl ether and 200 ml of 2N hydrochloric acid is added under ice cooling. The organic phase is washed with 250 ml of 2N hydrochloric acid and with 2 x 200 ml of 10*-ig sodium bicarbonate solution. Drying over sodium sulfate and evaporation of the solvent gives 15.4 g of 2. c) (4R)-4-(4'-carboxy-2'-methyl-butenyl)-2,2-dimethyl-oxa-zolidine-3-carboxylic acid tert-butyl ester (3). To a solution of 5.25 g of diisopropylamine in 200 ml of dry tetrahydrofuran is added at 0° 34.5 ml of a 1.6 molar solution of butyllithium in hexane. It is cooled to -75°C, added dropwise over the course of 10 minutes to a solution of 15 g of acetate 2 according to b) in 100 ml of tetrahydrofuran and, after 5 minutes, added to a solution of 8 g of tert-butyldimethylsilyl chloride in 30 ml of 1,3 -dimethyl-3,4,5,6-tetrahydro-2-(1H)-pyrimidinone The mixture is allowed to warm to room temperature, heated for 2 hours under reflux, cooled to room temperature, 230 ml of 45 *-ig are added ammonium fluoride solution, stirred for 20 hours at room temperature and evaporated. To the oily evaporation residue of the organic phase, under ice-cooling, add 150 ml of n-sodium hydroxide solution and the mixture is extracted with 2 x 200 ml of dichloromethane. The aqueous phase is acidified with 300 ml of 20 *-ig citric acid solution and extracted with 3 x 300 ml of dichloromethane. The organic phases are washed with 20 *-ig sodium chloride solution, dried over sodium sulfate and evaporated. Chromatography of the residue on 50 g of silica gel with hexane:ethyl acetate = 1:1 as eluent gives 11 g of solid 3. d) (4R)-4-(4'-carbethoxy-2'-methyl-butenyl )-2,2-dimethyl-oxazolidine-3-carboxylic acid tert-butyl ester (4).

d,a) Starting from acid 3.

To an ice-cooled solution of 7.8 g of carboxylic acid 3 according to c) in 100 ml of dry dichloromethane, 3.9 ml of 1-amino-1-chloro-N,N,2-trimethylpropene are added dropwise over the course of 10 minutes. After 30 minutes at 0<*>, a solution of 2.2 g of pyridine in 80 ml of ethanol is added over the course of 20 minutes. After stirring for 12 hours at room temperature, dilute with 100 ml of dichloromethane and wash with 2 x 100 ml of water. The organic phase is dried over sodium sulphate and evaporated. Chromatography of the residue on silica gel with hexane:ethyl acetate - 10:1 gives 6.5 g of ester 4, [a]n - +6.17° (c-1, CHCl3).

Elemental analysis for C18<H>31NO5:

Calculated: C 63.32*, H 9.15*, N 4.10*;

Found: C 63.4*, H 9.2*, N 4.5*.

d,b) Based on apple mixture 1.

A solution of 8 g of alcohol 1 according to a) and 0.05 ml of propionic acid in 10.5 ml of orthoacetic acid triethyl ester is heated under slow distillation of ethanol for 14 hours to 135-140°. It is evaporated under high vacuum at 40°. Chromatography of the residue on silica gel with hexane: ethyl acetate = 10:1 gives 8 g 4..

e) (4R)-2,2-dimethyl 1-4-(5'-hydroxy-2'-methyl-pent-1*-enyl)-oxazolidine-3-carboxylic acid tert-butyl ester (5.).

To a solution of 14.5 g of 4 according to d) in 250 ml of absolute diethyl ether, add 1.61 g of lithium aluminum hydride in portions at 0". It is stirred for 18 hours at 0-2° and, while cooling with acetone/dry ice, is added a solution of 5 g of potassium hydrogen sulfate in 60 ml of water. It is filtered and washed with 34 x 200 ml of diethyl ether. The organic phase is washed with 3 x 80 ml of N hydrochloric acid, with 3 x 80 ml of saturated sodium bicarbonate solution, with 2 x 200 ml of saturated sodium bicarbonate solution, dried over sodium sulfate and evaporated in. Chromatography on silica gel with hexane:ethyl acetate = 1:1 gives 11.3 g of 5,

Elemental analysis for C15H22NO4:

Calculated: C 64.19*, H 9.77*, N 4.68*;

Found: C 63.6*, H 9.8*, N 4.7*.

f) (4R)-4-(5'-brom-2'-methyl-pent-1*-enyl)-2,2-dimethyl-oxazolidine-3-carboxylic acid tert-butyl ester (6).

At 0-2" add, to a solution of 4.4 g of alcohol 5. according to e) in 200 ml of dichloromethane, 4.87 g of tetrabromomethane, 3.85 g of triphenylphosphine and 0.6 ml of pyridine. After 12 hours at 0- 2°, a further 1 g of each of tetrabromomethane and triphenylphosphine is added and stirred for 6 hours at 0°. It is evaporated, taken up in ethyl acetate, filtered and evaporated. Chromatography on silica gel with hexane:ethyl acetate = 10:1 gives 4, 5 g 6,

Elemental analysis for Ci^HgsNOsBr:

Calculated: C 53.04*. E 7.79*, N 3.87*, Br 22.06*;

Found: C 53.1*, H 7.7*. N 3.9*, Br 21.6*.

g) (4R)-2,2-dimethyl-4-(2'-methyl-5'-diisopropylphosphono-pent-1'-enyl)-oxazolidine-3-carboxylic acid tert-butyl ester (7).

A solution of 10.9 g of bromide 6 in 22 ml of triisopropyl phosphite is heated at 100 mbar for 24 hours to 135-140°. Excess reagent is evaporated at 0.1 mbar/60°. Chromatography of the residue on silica gel with hexane:ethyl acetate = 1:1 gives 10.7 g 7. h) N-((2R)-1-hydroxy-4-methyl-7-dliisopropylphosphono-hept-3-en-2-yl )-carbamic acid tert-butyl ester (8).

To a solution of 3 g of 7 according to g) in 100 ml of ethanol, add 3 g of Amberlyst® 15 (H+<-> form). It is stirred for 20 hours at room temperature, filtered, evaporated and chromatographed on 50 g of silica gel. Elution with ethyl acetate:methanol = 10:1 gives 2.3 g of 8, [α]D = -5.9' (c-1, CHCl 3 ).

Elemental analysis for CigHsgNO^P:

Calculated: C 56.0*, H 9.4*, N 3.44*, P 7.6*;

Found: C 55.4*, H 9.3*, N 3.4*, P 7.3*.

i) (2R)-2-tert-butoxycarbonylamino-4-methyl-7-diisopropylphosphono-3-heptenoic acid (9).

in ,a) 0ks. vdas. 1on with chrome svre.

At 0-5°, 0.84 ml of a solution, which is 3.25-molar of chromium trioxide and 5.29-molar of sulfuric acid, is added dropwise to a solution of 0.5 g of alcohol 8 according to h) in 15 ml of acetone. It is stirred for 30 minutes at 0° and 35 minutes at room temperature, 4 ml of isopropanol, 80 ml of ethyl acetate and 30 ml of 20% sodium chloride solution are added and filtered. The water phase is extracted with 3 x 20 ml of ethyl acetate. The organic phase is dried over sodium sulfate and evaporated. Chromatography on 20 g of silica gel with hexane:ethyl acetate:acetic acid = 16:10:1 gives 0.34 g 9, [a]j) = -35.25° (c-1.39, CHCl3),

<13>C-NMR (75 MHz, CDCl 3 ): 173.8 (CO 2 H); 155.0 (OCON);

140.4 (C(4)); 121.1 (C(3)); 79.5 (OC(CH 3 ) 3 ); 70.3 (OHCH); 52.1 (C(2)); 39.7 (d, J=18, C(5)); 28.3 ((CH 3 ) 3 C); 25.7 (d, J=142, C(7)); 24.0 ((CH3)2CH;

20.2 (d, J=5, C(6)).

1,b) Oxidation with platinum oxygen.

To a solution of 3 g of alcohol 8 according to h) in 105 ml of dioxane is added at 55° a suspension of platinum in 45 ml of water, prepared by hydration and degassing of 1 g of platinum oxide in 45 ml of water. At 55-60<*> oxygen is passed through under vigorous stirring (approx. 1900 rpm). It is filtered through Celite, washed with 2 x 80 ml of water and the filtrate is evaporated at 40° under high vacuum. Dissolve it in 200 ml of water, add 1 g of sodium bicarbonate and 50 ml of 20

*—lg sodium chloride solution and extracted with 3 x 100 ml ethyl acetate. The organic phases are dried over sodium sulfate. Filtration and evaporation gives 1.8 g of adduct 8. The water phase is acidified with approx. 20 ml of n-sulphuric acid and extracted with 5 x 120 ml of ethyl acetate. Drying over sodium sulphate, evaporation and chromatography of the residue according to i,a) gives 0.8 g of acid 9.

j) (2R)-2-amino-4-methyl-7-phosphono-3-heptenoic acid (10).

A solution of 3.3 g of acid 9 according to i) and 2.6 g of N,0-bis-trimethylsilylacetamide is stirred for 1 hour under argon at room temperature. After adding 4.4 g of trimethylbromosilane, stir for 24 hours. At 0°, 400 ml of water is added dropwise to the reaction mixture and stirred for 30 minutes. The organic phase is separated and washed with 3 x 50 ml of water. The aqueous phases are extracted with 3 x 30 ml of dichloromethane and evaporated at 40° under high vacuum to 10 ml. Chromatography on 20 ml of Dowex® 50 Wx8 with water as eluent and lyophilization of the eluate gives 0.4 g of 10 as an amorphous, white powder with a melting point of 252° (cleavage); [oc]d = -86.5°

(c-1, H 2 O).

Elemental analysis for C3H15NO5P.I H20:

Calculated: C 37.95*, H 6.9*: N 5.5*;

Found: C 36.3*, H 6.5*, N 5.6*.

A sample is derivatized for analysis of enantiomeric purity with (R)-(+)-methoxy-trifluoromethyl-phenylacetic acid chloride to amide. 3-H-NMR analysis (300 MHz) by integration of the 0CH 3 signals gives 2 94* (2R)-isomer (3.24 ppm) and 6* (2S)-isomer (3.17 ppm).

Example 7: (2R)-2-amino-7-phosphono-3-heptenoic acid.

a) (4R)-2,2-dimethyl-4-(1'-hydroxy-prop-2'-enyl)-oxazolidine-3-carboxylic acid tert-butyl ester ( 1 ).

To a solution of 25 g of (4S)-2,2-dimethyl-4-formyl-ox-azolidine-3-carboxylic acid tert-butyl ester (according to example 5c) in 300 ml of dry tetrahydrofuran is added, during 30 minutes at 0 -5", 60 ml of a 2.4 M solution of vinylmagnesium bromide in tetrahydrofuran. It is stirred for 1 hour at 0°, the mixture is allowed to warm to room temperature and it is stirred for 1 hour at room temperature. While cooling to 10°, 300 ml buffer solution (1-molar, phosphate, pH=7). After 10 minutes it is filtered, extracted with 2 x 150 ml ethyl acetate and washed with 2 x 100 ml water. The aqueous phase is extracted with 2 x 100 ml ethyl acetate. The organic extracts are dried over sodium sulfate and evaporate in. Chromatography of the residue on silica gel with hexane:ethyl acetate = 4:1 gives 24.2 g of epimer mixture 1.

Elemental analysis for C13H23NO4:

Calculated: C 60.68*, H 9.01*, N 5.44*;

Found: C 60.7*, H 9.1*, N 5.6*.

b) (4R)-4-(4'-ethoxycarbonylbutenyl)-2,2-dimethyl-oxazolidine-3-carboxylic acid tert-butyl ester (2).

A solution of 22.5 g of alcohol 1 according to a) and 0.3 ml of propionic acid in 38.5 ml of orthoformic acid triethyl ester is heated under slow distillation of ethanol for 4 hours to 135-140°C. It is evaporated under high vacuum at 50° and chromatographed on 300 g of silica gel. Elution with hexane-rethyl acetate = 4:1 gives 23.9 g of 2, [oc]D - -10.0<*> (c-1.5, CHCl3).

Elemental analysis for C17H29NO5:

Calculated: C 62.36*, H 8.93*, N 4.28*;

Found: C 62.2*, H 8.9*, N 4.4*.

c) (4R)-2,2-dimethyl-4-(5'-hydroxy-pentenyl)-oxazolidine-3-carboxylic acid tert-butyl ester (3).

To a solution of 23.5 g of 2 according to b) in 550 ml of absolute diethyl ether, 2.7 g of lithium aluminum hydride are added in portions at 0-2°. After stirring for 3 hours at 0-2', it is added dropwise while cooling to a solution of 25 g of potassium hydrogen sulphate in 250 ml of water. It is filtered through Celite® and washed well with diethyl ether. The organic phase is washed with 2 x 200 ml N hydrochloric acid and with 2 x 250 ml 10*-ig sodium bicarbonate solution. The aqueous phases are extracted with 2 x 100 ml of ether. The organic phases washed with 20

*-ig sodium chloride solution, dried over sodium sulphate and evaporated. Chromatography on silica gel with hexaneethyl acetate as eluent gives 18.6 g 3, [a]j) = -10.1° (c=1.4, CHCl 3 ).

Elemental analysis for C15H27NO4<:>

Calculated: C 63.13*. H 9.54*, N 4.91*;

Found: C 63.0*. H 9.5*, N 5.0*.

d) (4R)-4-(5'-bromopentenyl)-2,2-dimethyl-oxazolidine-3-carboxylic acid tert-butyl ester (4).

To a solution of 18.5 g of alcohol 3 according to c), 28.2 g of tetrabromomethane and 22.3 g of triphenylphosphine in 600 ml of dichloromethane, 7 ml of pyridine are added dropwise at 0°. It is stirred for 12 hours at 0-2°, evaporated, taken up in 150 ml of ethyl acetate, filtered, evaporated to 50 ml and chromatographed on 200 g of silica gel. Elution with hexane:ethyl acetate 10:1 gives 19.9 g of bromide 4, [α]D = -18.9° (c = 1, CHCl 3 ).

Elemental analysis for CisHgfcNOsBr:

Calculated: C 51.73*, H 7.53*, N 4.02*, Br 22.94*;

Found: C 51.7*, H 7.7*, N 4.2*, Br 23.0*. e) (4R)-2,2-dimethyl-4-(5'-di-2-propylphosphono-pentenyl)-oxazolidine-3-carboxylic acid tert-butyl ester (5).

A solution of 19.9 g of bromide 4 according to d) in 60 ml of triisopropyl phosphite is heated at 100 mbar for 20 hours to 130-135°. Excess reagent is distilled off at 60°/0.1 mbar, the residue is chromatographed on 250 g of silica gel. Elution with hexane:ethyl acetate =1:1 gives 20.6 g of phosphonic acid ester 5, [ot]D = -8.6° (c = 0.8, CHCl3).

Elemental analysis for Cgi^QNO^P:

Calculated: C 58.18*, H 9.30*. N 3.23*, P 7.15*;

Found. C 57.4*, H 9.3*, N 3.2*, P 7.5*.

f) N-((2R)-1-hydroxy-7-(diisopropylphosphono-hept-3-en-2-yl)-carbamic acid tert-butyl ester (6).

A solution of 20.6 g of 5. according to e) in 800 ml of methanol is stirred for 20 hours with 30 g of Amberlyst® 15 (H+<->form) at room temperature. It is filtered, washed with methanol, evaporated and chromatographed on 100 g of silica gel. Elution with ethyl acetate gives 14.8 g of 6, [α]D - -3.6° (c = 1.5, CHCl 3 ).

Elemental analysis for CigB^NOfcP:

Calculated: C 54.95*, H 9.22*, N 3.56*, P 7.87*;

Found: C 53.6*, E 9.0*, N 3.4*, P 9.0*.

g) (2R )-2-tert-butoxycarbonylamino-7-diisopropylphosphono-3-heptenoic acid (7).

To a solution of 7.4 g of alcohol 6 according to f) in 300 ml of acetone, 15 ml of a solution, which is 3.25 molar on chromium trioxide and 5.29 -molar of sulfuric acid. It is stirred for 2 hours at 0-2°, 4 hours at room temperature and then 30 ml of isopropanol, 300 ml of ethyl acetate and 200 ml of 20% sodium chloride solution are added. The water phase is extracted with 3 x 250 ml of ethyl acetate, the organic phases are dried over sodium sulphate and evaporated. Chromatography on 200 g of silica gel with hexane:ethyl acetate:acetic acid = 16:10:1 gives 4.55 g of acid 7, [α]u = -24.9° (c = 0.8, CHCl 3 ).

h) (2R)-2-amino-7-phosphono-3-heptenoic acid (8).

A solution of 3.1 g of acid 7 and 3 ml of N,0-bis-trimethyl-silylacetamide in 200 ml of dry dichloromethane is stirred for 1 hour at room temperature. 3.5 ml of trimethylbromosilane is added and stirred for 30 hours at room temperature. The volatile parts are evaporated off, the residue is taken up in 50 ml of dichloromethane and 250 ml of water is added at 0-2°. The water phase is separated and evaporated to 10 ml under high vacuum. Chromatography on 20 ml of Dowex® 50 Wx8 with water as eluent and lyophilization of the eluate gives 1.04 g of 8 as an amorphous powder, [oc]D = -65.2° (c = 1, H 2 O).

<13>C-NMR (75 MHz, D 2 O): 172.8 (CO 2 H); 140.3 (C(4)); 122.2

(C(3)); 56.4 (C(2)); 33.3 (d, J=17, C(5)), 27.3 (d, J=134, C(7)); 22.6 (d, J=4, C(6)).

A sample is derivatized for analysis of enantiomeric purity with (R)-(+)-methoxytrifluoromethyl-phenylacetic acid chloride followed by dlazomethane to the amide trimethyl ester.

^-H-NMR analysis (300 MHz) by integration of the 0CH3 signals gives 2 95* (2R)-isomer (3.54 ppm) and < 5* (2S)-Isomer (3.37 ppm).

Example 8: (2R)-2-amino-4-fluoro-5-phosphono-3-pentenoic acid (7). a) (4R)-4-(2'-carbonethoxy-2'-fluoro-vinyl)-2,2-dimethyl-oxazolidine-3-carboxylic acid tert-butyl ester (i).

To a suspension of 13 g of zinc powder and 2 g of copper (I) chloride in a solution of 8.2 g of (4S)-2,2-dimethyl-4-formyl-oxazolidine-3-carboxylic acid tert-butyl ester (according to example 5c) in 200 ml of dry tetrahydrofuran and 4.1 g of acetic anhydride, add, while stirring and heating, 8.1 g of dichlorofluoroacetic acid methyl ester (argon atmosphere). It is boiled for 2 hours under reflux, cooled, diluted with diethyl ether, filtered through Celite® and the filtrate evaporated. Chromatography of the residue on silica gel with hexane:ethyl acetate = 19:1 as eluent gives 5.07 g 1, mass spectrum (field desorption); 303 (M').

1-H-NMR (60 MHz, CDCl3): i.a. 5.93 (dxd, J=31 and 8.5, H-C(1')).

b) (4R)-2,2-dimethyl-4-(2'-fluoro-3*-hydroxy-propenyl)-oxazolidine-3-carboxylic acid tert-butyl ester (2).

To a solution of 4.9 g of ester 1 according to a) in 160 ml of absolute diethyl ether, 39 ml of a 1M solution of diisobutylaluminum hydride in hexane is added dropwise at 0-5°. It is stirred for 1 hour at 0-5°, 80 ml of ethyl acetate is added followed by 25 ml of 2N caustic soda, whereby the temperature is kept below 25°. It is stirred for 30 minutes at room temperature, 50 g of sodium sulphate is added, filtered and washed with ethyl acetate. Drying the filtrate with sodium sulfate, Evaporation and chromatography on 100 g of silica gel with hexane:ethyl acetate = 3:1 gives 3.7 g of 2, [a]p - +2.5 (c = 2.5, CHC13):.

Elemental analysis for C13C22NO4F:

Calculated: C 56.72*, H 8.06*, N 5.09*;

Found: C 56.2*, H 8.2*, N 5.1*.

c) (4R)-4-(3'-chromo-2'-fluoro-propenyl)-2,2-dimethyl-oxazolidine-3-carboxylic acid tert-butyl ester (3).

6.63 g of tetrabromomethane and 5.24 g of triphenylphosphine are added to a solution of 3.7 g of alcohol 2 according to b) in 200 ml of dry dichloromethane at 0-2° over the course of 10 minutes. After stirring for 15 hours at 0-2°, it is evaporated, taken up in 80 ml of ethyl acetate, filtered and the filtrate is evaporated. Chromatography of the residue on 50 g of silica gel with hexane:ethyl acetate = 4:1 gives 3.7 g of bromide 3, [oc]D = +12.7° (c - 1, CEC13).

Elemental analysis for C13H21<N>BRFO3:

Calculated: C 46.17*, H 6.26*, N 4.14*;

Found: C 46.4*. H 6.3*, N 4.2*.

d) (4R)-2,2-dimethyl-4-(2'-fluoro-3'-di-2-propylphosphono-propenyl)-oxazolidine-3-carboxylic acid tert-butyl ester (4).

A solution of 3.7 g of bromide 3 according to c) in 30 ml of tri-2-propylphosphite is heated at 100 mbar for 17 hours to 130-135°. Excess reagent is evaporated at 90°/0>l mbar. Chromatography of the residue on 100 g of silica gel with hexane-ethyl acetate = 3:1 gives 2.8 g of phosphonate 4; [cx]d = -8.6° (c = 3, CHCl 3 ).

Elemental analysis for C19<H>35NFO6P:

Calculated: C 53.89*, H 8.33*. N 3.31*;

Found: C 53.7*, H 8.4*, N 3.4*.

e) N-((2R)-4-fluoro-1-hydroxy-5-di-2-propyl-phosphono-pent-3-en-2-yl)-carbamic acid tert-butyl ester (5).

A solution of 2.3 g of phosphonate 4 according to d) in 250 ml of methanol is stirred for 20 hours at room temperature with 5 g of Amberlyst®-15 (H+<-> form). It is filtered, evaporated and chromatographed on 80 g of silica gel. Elution with ethyl acetate gives 1.31 g of alcohol 5, [α]D = -21.2° (c-1, CHCl 3 ).

Elemental analysis for Ci3H3iNFOgP:

Calculated: C 52.31*, H 8.51*, N 3.81*;

Found: C 50.2*, H 8.2*, N 3.7*.

f) (2R)-2-tert-butoxycarbonylamino-4-fluoro-5-di-2-propylphosphono-3-pentenoic acid (6).

To a solution of 1.3 g of alcohol 5. according to e) in 80 ml of acetone at 0-2°, 2.5 ml of a solution which is 3.25 M on chromium trioxide and 5.29 M on sulfuric acid is added. It is stirred for 2 hours at 0-2° and the mixture is allowed to warm to room temperature over 4 hours. After adding 20 ml of 2-propanol, 100 ml of ethyl acetate and 50 ml of a 20% NaCl solution, the water phase is separated and extracted with 4 x 100 ml of ethyl acetate. Drying of the organic phases with sodium sulfate, evaporation and chromatography on 70 g of silica gel with hexane:ethyl acetate:acetic acid = 10:16:1 as eluent gives 0.87 g of acid 6, [a]D = -72.9° (c = 0.8, CHCl 3 ).

g) (2R)-2-amino-4-fluoro-5-phosphono-3-pentenoic acid (7).

A solution of 0.8 g of 6 according to f) and 0.84 ml of N,0-bis-trimethylsilylacetamide in 80 ml of dry dichloromethane is stirred for 1 hour at room temperature. After adding 0.98 ml of trimethylbromosilane, the mixture is stirred for 30 hours at room temperature. The volatile parts are evaporated off, the residue is dissolved in 50 ml of dichloromethane and 200 ml of water is added at 0-5°. The organic phase is separated and washed with 2 x 50 ml of water. The water phases are evaporated under high vacuum to 10 ml. Chromatography on 30 ml of Dowex® 50 Wx8 with water as eluent and lyophilization of the eluate gives 0.22 g of 7, [a]D = -44.8° (c = 0.5, H2=).

Mass spectrum (fast atom bombardment): 214, (M+H)<+>.

<13>C-NMR (75 MHz, D2O): 172.7 (C02H): 161.5 (dxd, J = 262

and 12, C(4)); 100.9 (t, J ca. 11, C(3)); 49.5 (C(2));

33.5 (dxd, J - 128 and 26, C(5)).

A sample is derivatized for analysis of enantiomeric purity with (R)-(+)-methoxy-trifluoromethylphenylacetic acid chloride to amide. <*>H-NMR analysis (300 MHz) gives, by integration of the 0CH 3 ~ signals, > 90* (2R)-isomer (3.49 ppm) and £ 10* (2S)-isomer (3.38 ppm).

Example 9: (2R)-2-amino-4-methyl-5-phosphono-3-pentenoic acid ethyl ester a) (2R,3S)-2-formylamino-3-hydroxy-4-methyl-4-pentenoic acid ethyl ester ( in).

aa) From 1. 1. 3. 3- tetramethyl- l. 3- disila- 2- azolidine- N- eddlk-svreetvlester.

To a solution of 2.26 ml of N-cyclohexyl-N-isopropylamine in 60 ml of absolute tetrahydrofuran is added at -20° 7.6 ml of a 1.6-molar solution of butyllithium in hexane. After 20 minutes it is cooled to -78° and a solution of 3 g of 1,1,3,3-tetramethyl-1,3-disila-2-azolidine-N-acetic acid ethyl ester in 60 ml of tetrahydrofuran is added dropwise. It is stirred for 1 hour at -78° and then 142 ml of an approx. 0.035-molar solution of cyclopentadienyl-bis-0-1,2:5,6-di in isopropylidene-D-glucofuranosyl-titanium(IV) chloride in ether and this is stirred for 17 hours at -78°. The reaction solution is transferred by means of a steel cannula under argon pressure to a vessel with a solution of 1.1 ml of methacrolein in 15 ml of tetrahydrofuran, cooled to -78°. The mixture is allowed to warm slowly to room temperature, it is stirred for 2 hours, 1.5 ml of water is added and filtered. The filtrate is diluted with 250 ml diethyl ether, washed with 3 x 250 ml approx. 10 *-ig sodium chloride solution and with 250 ml saturated sodium chloride solution. The aqueous phases are extracted with 2 x 250 ml of diethyl ether. The organic phases are dried over sodium sulphate, evaporated and dissolved hot in 150 ml of cyclohexane. On cooling, 1,2:5,6-di-O-isopropylidene-D-glucofuranose crystallizes. The mother liquor is evaporated, the residue is taken up in 120 ml tetrahydrofuran, 24 ml water and 4.5 ml acetic acid and stirred for 2 hours at room temperature. Evaporation under high vacuum at room temperature gives 10.6 g of residue, which contains (2R.3S)-2-amino-3-hydroxy-4-methyl-4-pentenoic acid ethyl ester.

A sample (5 mg) is derivatized for 2 hours with 0.2 ml of trifluoroacetic anhydride in 0.3 ml of dichloromethane. Capillary gas chromatography (Chirasil®-L-Val, 90-180°/2° per minute) gives 99.25* (2R,3S)-enantiomer (retention time Tret = 10.28 minutes and 0.75* (2R,3R) -enantiomer (retention time Tre-t => 11.48 minutes). It is then heated for 5.5 hours in 80 ml ethyl formic acid under reflux. Evaporation and chromatography on silica gel with hexane:ethyl acetate = 1:1 gives 1.64 g of formamide 1 .Analysis of a sample (5 mg) as acetate by gas chromatograph in (Chirasil®-L-Val, 160-180°, 1° per minute): 99.2* (2R,3S)-enantiomer (Tret = 13, 64 minutes).0.8* (2S,3R)-enantiomer (Tret <=> 13.94 minutes).

a,b) Starting from isocyanate diethyl ester.

To a solution of 24.88 g isocyanoacetic acid ethyl ester and 18.51 g methacrolein in 220 ml 1,2-dichloromethane is added at 50° 1.65 g (S )-N-methyl-N[2-dimethylamino)-ethyl]-1 -[(R)-1',2-bls-(diphenylphosphino)ferrocenyl]-ethylamine and 1.105 g of bis(cyclohexylisocyanide)gold(I)tetrafluoroborate. It is stirred for 5 hours at 50° under argon, evaporated, taken up in 400 ml of diethyl ether, filtered and the filtrate evaporated. Distillation of the evaporation residue under high vacuum (0.04 mbar) gives 33.62 g of a stereoisomer mixture of 5-(2-propenyl)-oxazoline-4-carboxylic acid ethyl ester of melting point 42-52'; MS: m/e - 183 (2*, M<+>), 110 (80*), 85 (100*). A solution of 33 g of this mixture in 74 ml of water and 33 ml of tetrahydrofuran is heated to reflux for 3 hours. Evaporation under vacuum gives 36.1 g of a mixture of stereoisomers 2-formylamino-3-hydroxy-4-methyl-4-pentenoic acid ethyl ester 2.

A sample (35 mg) is derivatized in 2 ml of dichloromethane with 0.05 ml of N.O-bis-trimethylsilylacetamide and analyzed by capillary gas chromatography (ChirasII®-L-Val, 150°): 89.1* (2R,3S)-isomer (Tret <=> 22.1 minutes), 5,8* (2S,3R)-isomer (Tret = 23.1 minutes), 2,8* (2R,3R)-isomer ( Tret = 24.3 minutes) , 2,3* (2S,3S)-isomer (Tret = 25.4 minutes).

To a solution of 20.2 g 2, 16.83 ml triethylamine and 0.62 g 4-(dimethylamino)pyridine in 300 ml dichloromethane, a solution of 11.42 ml of acetic anhydride in 50 ml of dichloromethane. After 30 minutes, wash twice with ice-cold 2N.2-hydrochloric acid and twice with 10 *g sodium chloride solution. The aqueous phases are extracted with 100 ml of dichloromethane. The evaporation residue of the organic phases which have been dried over sodium sulphate is dissolved in warm 1 hexane:ethyl acetate = 4:1. By slow cooling to approx. 30° crystallizes 1.82 g of racemic (2R<*>,2S<*>)-2-formylamino-3-acetoxy-4-methyl-4-pentenoic acid ethyl ester with melting point 98-106°. The mother liquor is cooled slowly to -12°C and kept for 1 hour at this temperature.

Filtration gives 15.04 g of acetate 3, melting point 73-75°, [cOd = -75.6° (c - 1, CHCI3), gas chromatographic analysis (Chirasil®-L-Val, 160-160°, 1° pr . minute);

(2R.3S) isomer 93.5* (Tret - 14.5 minutes), (2S,3R)-isomer 2.2* (Tret = 14.8 minutes), (2R,3R)-isomer 2.2*

(Tret = 16.8 minutes), (2S,3S)-isomer 2.1* (Tret = <1>7.1 minutes).

To a solution of (2R,3S)-2-formylamino-3-acetoxy-4-methyl-4-pentenoic acid ethyl ester (3) in 400 ml of absolute ethanol is added at -16°, 20.64 g of anhydrous potassium carbonate. After 4 hours of stirring at -18° to -11°C, 500 ml of buffer solution (1-molar, phosphate, pH - 7) is added dropwise. It is stirred for 30 minutes at room temperature and extracted 3 x 350 ml of dichloromethane. Chromatography of the evaporation residue of the organic phases dried over sodium sulfate on 1 kg of silica gel with hexane:ethyl acetate =1:2 as eluent gives 9.8 g of alcohol 1. b) (2R)-2-formylamino-4-methyl-5 -diisopropylphosphono-3-pentenoic acid ethyl ester (4).

To a solution of 14.19 g of 1 according to a) in 210 ml of 1,2-dichloroethane at 18-20°, 6.57 ml of thionyl bromide and, after stirring for 2 hours, 135 ml of water are added. After 15 minutes, the organic phase is separated and it is washed with 3 x 150 ml of ice water and once with 100 ml of ice-cooled, saturated sodium bicarbonate solution. The evaporation residue of the organic phase which has been dried with sodium sulphate is stirred dissolved in 60 ml of triisopropylphosphite for 17 hours at 75°/100 mbar. Surplus reagent is distilled off under high vacuum at 90°. Chromatography of the residue on 650 g of silica gel with ethyl acetate:methanol = 20:1 gives 10.88 g of phosphonic acid ester 4, [ot]D = -123.5° (c-1, CHCl 3 ). %-NMR analysis (300 MHz) during the addition of (IR )-1-(9'-anthracenyl)-2,2,2-trifluoroethanol shows an enantiomeric purity of > 90*. c) (2R)-2-amino-4-methyl-5-phosphono-3-pentenoic acid ethyl ester (£>).

To a solution of 10.3 g of 4 according to b) in 42 ml of dichloromethane, 23 ml of trimethylbromosilane are added dropwise at room temperature over the course of 15 minutes. After 21.5 hours, 42 ml are added

ethanol under ice-cooling and the whole is stirred further for 20 hours. It is evaporated, the residue is dissolved three times in each time 70 ml of toluene and evaporated again. The residue is dissolved in 42 ml of ethanol and 42 ml of propylene oxide is added. After

1.5 hours is filtered. Drying the filtrate under a vacuum desiccator over P2O5/KOH (3 hours/80") gives 6.17 g of 5;

[α]D - -78° (c = 0.6, H 2 O); melting point 194-197° (cleavage),

Elemental analysis for CgHi^NOgP:

Calculated: C 40.5156, H 6.80*, N 5.91*, P 13.06*;

Found: C 39.4*, H 7.08*, N 5.73*, P 12.98*.

A sample is derivatized for analysis of enantiomeric purity with (R)-(+)-methoxytrifluoromethyl-phenylacetic acid chloride and diazomethane to amide dimethylphosphonate and analyzed by 1-H—NMR (300 (MHz) by means of integration of the 0CH3 signals; ( 2R)-isomer > 93* (3.51 ppm), (2S)-isomer < 7* (3.37 ppm).

Example 10:

In an analogous manner as described in examples 1-3 or 5 and 8, the following can also be prepared: E-2-amino-5-phosphino-3-pentenoic acid ethyl ester, melting point 172-173°;

E-2-amino-5-phosphino-3-pentenoic acid butyl ester, melting point 160-161°;

E-2-amino-5-phosphono-3-pentenoic acid ethyl ester, melting point 167-168°;

E-2-amino-5-phosphono-3-pentenoic acid butyl ester, melting point 160-161°;

E-2-amino-5-phosphono-3-pentenoic acid octyl ester, m.p. 161-162';

E-2-amino-5-phosphono-3-pentenoic acid propyl ester, melting point 161-162°;

E-2-amino-5-phosphono-3-pentenoic acid pentyl ester, melting point 160-161°;

E-2-amino-5-phosphono-3-pentenoic acid isobutyl ester, melting point , 163-164°;

E-2-amino-5-phosphono-3-pentenoic acid secondary butyl ester, melting point 169-170°;

E-2-amino-4-methyl-5-phosphono-3-pentenoic acid methyl ester, m.p. 193-194°, [water:acetone (9:1)];

; E-2-amino-4-methyl-5-phosphono-3-pentenoic acid propyl ester,

melting point 184-185°, (water);

E-2-amlno-4-methyl-5 - ph o sf ono - 3-pentenoic acid-n-butyl ester , melting point 186-187°, [water:acetone (2:1)];

E-2-amino-4-methyl-5-phosphono-3-pentenoic acid isobutyl ester , , mp 181-182°, [water:acetone (9:1)];

E-2-amino-4-methyl-5-phosphono-3-pentenoic acid pentyl ester, melting point 207-208°;

E-2-amino-4-methyl-5-phosphono-3-pentenoic acid hexyl ester,

melting point 207-208°;

E-2-amino-7-phosphono-4-heptenoic acid butyl ester, melting point 186°;

E-2-amino-5-phosphono-4-pentenoic acid methyl ester, melting point 219-220°;

E-2-amino-5-phosphono-4-pentenoic acid ethyl ester, melting point 234°;

E-2-amino-5-phosphono-4-pentenoic acid butyl ester, melting point 239°; j E-2-amino-5-phosphono-4-pentenoic acid octyl ester, melting point 236°; E-2-amino-5-phosphono-4-pentenoic acid-2-hydroxyethyl ester, melting point 197°.

>

Example 11;

In an analogous way as described 1 example 10 or examples 4, 6, 7 and 8 can be further produced: E-2-amino-5-phosphono-4-pentenoic acid, melting point 219-220°; E-2-amino-5-methylphosphonyl-4-pentenoic acid, melting point 222°; E-2-amino-5-butylphosphonyl-4-pentenoic acid, melting point 232-233°; E-2-amino-5-octylphosphonyl-4-pentenoic acid, melting point 221-223°; E-2-amino-5-dodecylphosphonyl-4-pentenoic acid, melting point 211°; E-2-amino-6-phosphono-4-hexenoic acid, melting point 244-246°; E-2-amino-6-methylphosphonyl-4-hexenoic acid, melting point 145-150°; E-2-amino-6-butylphosphonyl-4-hexenoic acid, melting point 216°; E-2-amino-6-octylphosphonyl-4-hexenoic acid, melting point 209-210°; E-2-amino-6-dodecylphosphonyl-4-hexenoic acid, melting point 197-200°; E-2-amlno-7-phosphono-4-heptenoic acid, melting point 125° (cleavage); E-2-amino-5-phosphono-3-pentenoic acid, white amorphous powder, 1-H-NMR (D 2 O): 2.39 (dd, 2H, C(5)-H); 4.27 (d, 1H, C(2)-H); 5.53 (m, 1H, C(3)-H); 5.87 (m, 1H, C(4)-H), melting point after recrystallization from ethanol:water 191-192°; E-2-amino-4-methyl-5-phosphono-3-pentenoic acid, 1 H NMR (D 2 O): 1.73 (s, 3H, CH 3 ); 4.55 (s, 1H, C(2)-H); E-2-amino-5-methylphosphonyl-3-pentenoic acid, amorphous white powder, 1-H-NMR (D 2 O): 2.55 (dd, 2H, C(5)-H); 4.38 (d, 1H, C(2)-H); 5.64 (m, 1H, C(3)-H); 5.91 (m, 1H, C(4)-H); E-2-amino-5-phosphino-3-pentenoic acid, melting point 139-140°; E-2-amino-4-methyl-5-phosphino-3-pentenoic acid, melting point 176-177°; (2S)-E-2-amino-4-methyl-5-phosphono-3-pentenoic acid, mp 196°, [α]D = +97.1 ± 1.9° (c = 0.5; water); E-2-amino-4-methyl-5-methylphosphonyl-3-pentenoic acid, 1 H-NMR (D 2 O): 1.20 (d, 3H, CH 3 -P); 1.75 (d, 3H, CH3); 2.45 (d, 2H, c(5)-H); 4.50 (d, 1H, C(2)-H); 5.15 (m, 1H, C(3)-H); E-2-amino-2-methyl-5-phosphono-3-pentenoic acid, melting point 225-226° (from water); E-2-amino-3-methyl-5-phosphono-3-pentenoic acid, white amorphous powder, melting point 168°, *E-NMR (D 2 O): 1.50 (d, 3H, CE 3 ); 2.4 (m, 2H, CH2); 4.30 (s, 1E, C(2)-E); 5.60 (m, 1E, C(4)-E); E-2-amino-5-methyl-5-phosphono-3-pentenoic acid, white amorphous solid, ifl NMR (D 2 O): 1.05 (dd, 3E, CH 3 ); 2.45 (m, 1H, C(5)-E); 4.33 (d, 2E, C(2)-H); 5.5 and 5.9 (2m, 2E, C(3)-E and C(4)-E); E-2-amino-4-ethyl-5-phosphono-3-pentenoic acid, melting point 176°; E-2-amino-4-propyl-5-phosphono-3-pentenoic acid, melting point 193°; E-2-amino-4-butyl-5-phosphono-3-pentenoic acid, melting point 186-187°; E-2-amino-4-isopropyl-5-phosphono-3-pentenoic acid, melting point 201°; E-2-amino-4-tert-butyl-5-phosphono-3-pentenoic acid, melting point 252-253°; 1-E NMR (D 2 O): 0.95 (s, 9E, (CE 3 ) 3 C); Z-2-amino-4-tert-butyl-5-phosphono-3-pentenoic acid, 11-NMR (D 2 O): 1.08 (s, 9H, (CE 3 ) 3 C); 2.45 (m, 2H, CE2); 4.95 (d, 1E, C(2)-E); 5.20 (m, 1E, C(3)-E); E-2-amino-4-benzyl-5-phosphono-3-pentenoic acid, colorless needles, melting point 196-198°; E-2-amino-4-phenyl-5-phosphono-3-pentenoic acid, colorless needles, melting point 230-233°; E-2-amino-4-methyl-5-methylphosphono-3-pentenoic acid as by-product, melting point 149-150°.

Claims (6)

1. Process for the preparation of therapeutically useful unsaturated amino acid compounds of the formula: there R 1 means hydrogen, C 1-6 alkyl or hydroxy, R2 means hydrogen, C1-6-alkyl, phenyl-<C>1-6-alkyl, halogen or phenyl, R3 means hydrogen or C1_4~alkyl, R 4 means hydrogen or C 1-4 alkyl, R5 means carboxy or C1-4 alkoxycarbonyl, Rf means an unsubstituted amino group, A means an unsubstituted or one with C1-4-alkyl substituted a,co-Ci_3-alkylene residue or a direct bond and B means methylene or a direct bond, provided that A means an a,w-Ci_3 alkylene residue optionally substituted with C1_4 alkyl when B means a direct bond, and salts thereof, characterized by the fact that, in connection with the formula: there Z 1 means C 1-6 -alkyloxy, Z 2 means a group R 1 or C 1 -C 6 -Alkoxy, Zfc means C 1-6 -alkanoylamino or C 1-6 -alkoxycarbonylamino, and R 1 , R 2 , R 3 . R 4 , R 5 , Å and B have the meaning indicated above, liberates the protective groups Z 1 and optionally Z 1 and/or Z 2 by treatment with a trilower alkylhalosilane and optionally hydrolyzes an obtained ester of formula (I) where R 5 means C 1-4 -Alkoxycarbonyl , to the corresponding acid where R 5 means carboxy, and/or transfers a free compound to a salt or an obtained salt to the free compound or to another salt. 2. Method according to claim 1, characterized in that one starts from a compound of formula II where the group Z5 means tert-butyloxycarbonylamino. 3. Process according to claim log2, characterized in that trimethylbromosilane is used as trilower alkylhalosilane and that the release of the protected groups Z^, Z2 and/or Z^ takes place in a halogenated hydrocarbon, preferably dichloromethane as a solvent or diluent and that a hydrogen halide scavenger is added compound, preferably propylene oxide 1 mixture with ethanol. 4. Process according to claims 1 to 3 for the production of (2R)-E-2-amino-4-methyl-5-phosphono-3-pentenoic acid or a pharmaceutically acceptable salt thereof, characterized in that one starts from the corresponding starting mixtures. 5. Method according to claims 1 to 3 for the production of (2R)-E-2-amino-4-methyl-5-phosphono-3-pentenoic acid ethyl ester or a pharmaceutically acceptable salt thereof, characterized in that one starts from the corresponding starting compounds. 6. Process according to claims 1 to 3 for the production of (2R)-E-2-amino-4-methyl-7-phosphono-3-heptenoic acid or a pharmaceutically acceptable salt thereof, characterized in that one starts from the corresponding starting compounds.