EP0362267A1 - 3-o-glycosyl 16-membered macrolide antibacterials and related derivatives - Google Patents

Abstract

3-O-glycosyl derivatives of 16-member macrolides such as O-alpha-L cladinosyle- (1-> 3) -12,13-dehydro-12,13-deoxorosaramicin, 2 '', 4 '', 4 '' '-tri-O-acetyl-O- (4'-O-phenoxyacetyl-alpha-L-cladinosyl) - (1-> 3) -desmycosin, as well as their pharmaceutically acceptable acid addition salts useful as antibacterial substances.

Description

3-O-GLYCOSYL 16-MEMBERED MACROLIDE ANTIBACTERIALS AND RELATED DERIVATIVES

This invention relates to 3-O-glycosyl 16-membered macrolide antibacterials, such as 2'',4'',4'''- tri-O-acetyl-O-(4'-O-phenoxyacetyl- α-L-cladinosyl)-(1→3)- desmycosin and O-α-L-cladinosyl-(1→3)-12,13-dehydro- 12,13-deoxorosaramicin, related derivatives, pharmaceutically acceptable acid addition salts thereof, pharmaceutical compositions containing them and a method of eliciting an antibacterial response using the novel antibacterials or pharmaceutical compositions containing them.

Several 3-O-glycosyl derivatives are found among the naturally occurring 12- and 14-membered macrolides. For example, among the 12-membered macrolides, methymycin is disclosed in J. Am. Chem. Soc, 1956, 78, p. 6390, and neomethymycin is disclosed in Tetrahedron, 1958, 3 , p. 255. Among the 14-membered macrolides, erythromycin is disclosed in J. Am. Chem. Soc., 1957, 79, p. 6062; oleandomycin is disclosed in J. Am. Chem. Soc., I960, 82, p. 3225; and lankamycin is disclosed in J. Am. Chem. Soc, 1970, 92, P. 4129. However, there is no disclosure of 3-O-glycosyl 16-membered macrolide antibacterials available synthetically or occuring naturally. This invention may be summarized as a compound represented by formula I :

wherein R₁ is a glycosyl group, represented by the formula II:

wherein R_q and each R_t are independently hydrogen, hydroxy, acyloxy, loweralkoxy, aralkoxy, N- loweralkylamino-carbonyloxy, N-aralkylamino carbonyloxy, or arylsulfonyloxy (-OSO₂Ar) and R_s and R_w are independently hydrogen, lower alkyl or -CH₂OH; or represented by the formula IIA:

wherein each R_a is independently hydrogen, lower alkyl, or CH₂OH and each R_b is independently hydrogen, hydroxy, acyloxy, lower alkoxy, aralkoxy, N- loweralkylaminocarbonyloxy, N-aralkylaminocarbonyloxy or arylsulfonyloxy and n is 1, 2, 3, or 4;

R₂ is hydrogen or an acyl group;

X is hydrogen, hydroxy, an acyloxy group

or wherein each R₂ is independently as defined hereinabove; Y is hydrogen, a formyl group, methyl, HC=NNH-aralkyl, , or

wherein m is 0,1, or 2 and Q is independently CR₃R₄, NR₃,

O, S, SO₂ CR₃jOR₄, wherein R₃ and R₄ are independently hydrogen, lower alkyl, aralkyl, G-substituted aralkyl, aryl and G-substituted aryl wherein G is independently one or more of halogen, trifluoromethyl, lower alkoxy or (C₂-C₇)alkanoyl; is a 12,13 double bond or a 12,13-oxo moiety; Z is hydrogen, hydroxy, an acyloxy group, a N,N-di(loweralkyl) amino group,

loweralkoxycarbonyloxy, aralkoxycarbonyloxy, N- loweralkylaminocarbonyloxy, or N-aralkylaminocarbonyloxy wherein R₂ is def ined above and R₅ and R₆ are independently hydrogen , lower alkyl or acyl groups ; or a pharmaceutically acceptable acid addition salt thereof .

In a preferred class of compounds , R₁ is an α- L-glycosyl group represented by formula II . In an other preferred class of compounds R ₁ is α-L -clandinosyl or tetrahydropyranyl , X is hydrogen , hydroxy, or

wherein R₂ is as defined previously, Y is menthyl or formyl, Z is hydrogen, acyloxy, hydroxy, or wherein R₂, R₅ and R₆ are as defined previously.

In still another preferred class of compounds,

R₁ is

wherein R₂ is as defined previously, X is hydroxy or acyloxy, is a 12,13 double bond, and Z is

wherein R₂, R₅ and R₆ are as defined previously. Especially compounds within the class are those wherein

R₁ is

or

X is hydroxy or acetyl , Z is

or

and

R is acetyl .

Preferred individual compounds are

O-(α-L-cladinoxyl)-(1→3)-12,13-dehydro-20-dihydro-12,13,20-dideoxorosaramicin, O- (α-L-clandinosyl)-(1→3)-12,13-dihydro-12,13-deoxorosaramicin, O-(4'-O-acetyl-α-L-cladinosyl)-(1 →3)-2' ' -O- acetyl-12,13-dehydro-20-dihydro-12,13,20- dideoxorosaramicin, O-(4'-O-acetyl-α-L-cladinosyl)-(1→3)-2''-O- acetyl-12,13-dehydro-12,13-deoxorosaramicin, O-tetrahydropyranyl-(1→3)-rosaramicin, 2'',4'',4''', tri-O-acetyl-19-deformyl-O-(4'-O- phenoxyacetyl-α-L-cladinosyl)-(1→3)-demycosin,

2'',4'',4'''-tri-O-acetyl-O-(4,-O- phenoxyacetyl-α-L-cladinosyl)-(1→3)-desmycosin,

2' ' ,4' ' ,4' ' '-tri-O_-acetyl-20-deoxy-20-dihydro- O- (4'-O-phenoxyacetyl-α-L-cladinosyl)-(1→3)-desmycosin, O - (α-L-cladinosyl)-(1→3)-19-deformyldesmycosin, O-(α-L-cladinosyl)-(1→3)-20-deoxo-20- dihydrodesmycosin, O-α-L-cladinosyl-(1→3)-demycosin.

The invention also includes the use of a compound of formula I for the preparation of a pharmaceutical composition useful for treating bacterial infection and a method for making a pharmaceutical composition comprising mixing a compound of formula I with a pharmaceutically acceptable carrier.

The compounds of this invention show high serum levels and are useful as antibacterials against susceptible bacterial infections, especially those caused by Gram-positive organisms.

This invention also provides a pharmaceutical composition comprising an antibacterially effective amount of a compound represented by formula I in admixture with a pharmaceutically acceptable carrier therefor.

This invention further provides a method of eliciting an antibacterial effect against susceptible bacterial infections, wherein an antibacterially effective amount of a compound represented by formula I or pharmaceutical compositions thereof is administered to an animal having a susceptible bacterial infection.

The compounds of this invention have stereochemical configuration indicated for the structure of compounds of formula I, and it is to be understood that the stereochemical configuration is identical to that of tylosin. The stereochemistry of the 12,13-oxo moiety, when present in the compounds of formula I, is indicated below:

The term "acyl group" as used herein means (C₂-C₇)alkanoyl; (C₂-C₇ )alkanoyl substituted by chloro, lower alkoxy, aryl, aralkoxy, or aryloxy; aroyl; and substituted aroyl; said aroyl substituents being one or more of halogen, nitro, lower alkoxy, or lower alkyl,

The term "acyloxy" means the "acyl group" as defined herein univalently bonded to divalent oxygen and includes inter alia, acetyloxy, butyryloxy, iso- valeryloxy, phenylacetyloxy, benzoyloxy, p-methoxybenzoyloxy.

The term "lower alkyl" as used herein means straight and branched-chain alkyl groups of one to six carbons including methyl, ethyl, propyl, butyl, pentyl, hexyl and the corresponding branched-chain isomers thereof such as iso-propyl, tert- or sec-butyl, iso- valeryl and iso-hexyl. Methyl is the preferred alkyl group .

The term "lower alkoxy" means "lower alkyl" groups univalently bonded to divalent oxide and includes inter alia, methoxy, ethoxy, and propoxy.

The term "aryl" means phenyl and biphenyl optionally substituted by lower alkyl.

The term "halogen" means fluoro, chloro and bromo, preferably fluoro and chloro.

The term "aralkyl" means lower alkyl substituted by aryl including benzyl, α- and β-phenethyl and α- and β-(o-tolyl)ethyl. "Aralkoxy" refers to "aralkyl" as defined hereinabove univalently bonded to divalent oxygen.

The term "aryloxy" refers to phenoxy and biphenyloxy.

The term "(C₂-C₇)alkanoyl" means carbonyl groups univalently bonded to "lower alkyl" groups and includes acetyl, propionyl, butyryl, iso-butyryl and iso-valeryl. The preferred (C₂-C₇) alkanoyl groups are acetyl, butyryl, iso-valeryl for R₁, R₂, R₃, R₄, R₅, and

Typical suitable chloro-substituted (C₂-C₇) alkanoyl groups include 2-chloro(C₂-C₇) alkanoyl such as 2-chloroacetyl and 2-chloropropanoyl. Typical suitable lower alkoxy (C₂-C₇) alkanoyls include methoxyacetyl, ethoxyacetyl, 2- and 3-methoxypropanoyl, and propoxyacetyl. Typical suitable aryl-substi tuted (C₂-C₇) alkanoyl groups include phenylacetyl and biphenylacetyl. Typical suitable aryloxy-substituted ( C₂-C₇) alkanoyls include phenoxyacetyl and biphenyloxyacetyl.

The term "aroyl" means substituted and unsubstituted benzoyl wherein the substituents are one or more of halogen, nitro, lower alkoxy or lower alkyl. Typical suitable substituted benzoyl include p-fluoro benzoyl, 3-chlorobenzoyl, 4-nitrobenzoyl, 3-nitrobenzoyl, p-ethoxybenzoyl, 3-chloro-4-nitrobenzoyl, 3-fluoro-4-methoxybenzoyl, 3-nitro-4-ethylbenzoyl and 3-chloro-4-methylbenzoyl.

Typical suitable G-substituted aryl groups include 4-fluorophenyl, 3-chlorophenyl, 4-trifluoromethylphenyl, 4-ethoxyphenyl, 4-acetylphenyl and 3- chloro-4-methoxyphenyl.

Typical suitable G-substituted aralkyl groups include 4-fluorobenzyl, 3-chlorophenylethyl, 4-methoxy-α-phenethyl, and 4-trifluoromethylbenzyl.

The term "N,N-di(loweralkyl)amino" means two "lower alkyl groups", each univalently bonded to a trivalent nitrogen atom, including dimethylamino, diethylamino, di-n-propylamino, methylpropylamino and diisopropylamino.

The term "lower alkoxycarbonyloxy" as used herein means "lower alkoxy" groups univalently bonded

0 to the carbonyl carbon of the carbonyloxy moiety (-C-0-) , including inter alia, methoxycarbonyloxy, ethoxycarbonyloxy and n - and iso-propoxycarbonyloxy.

The term "aralkoxycarbonyloxy" as used herein means an "aralkyl group" univalently bonded to a divalent oxide which in turn is univalently bonded to the carbonyl carbon of the carbonyloxy moiety including phenethoxycarbonyloxy, benzyloxycarbonyloxy, and o-tolylethoxycarbonyloxy.

The term "N-loweralkylaminocarbonyloxy" as used herein means one or two "lower alkyl group" univalently bonded to the trivalent amino moiety, -N- which in turn is univalently bonded to the carbonyl carbon of a carbonyloxy moiety, including N-methylaminocarbonyloxy N,N-dimethylaminocarbonyloxy, N-iso-propyl aminocarbonyloxy N,N-methylethylaminocarbonyloxy and N- tert-butylaminocarbonyloxy.

The term "N-aralkylaminocarbonyloxy" as used herein means one or two "aralkyl group" univalently

bonded to a trivalent nitrogen, i.e. -N- which in turn is univalently bonded to the carbonyl carbon of the carbonyloxy moiety, including N-benzylaminocarbonyloxy, N - (β-phenethyl)aminocarbonyloxy and N-o-tolylethylaminocarbonyloxy.

The term "arylsulfonyloxy" means "aryl" univalently bonded to the sulfur in sulfonyloxy including phenylsulfonyloxy and biphenyl sulfonyloxy.

In formula IIA, R_a is preferably hydrogen or methyl. R_b is preferably hydrogen or loweralkoxy.

Typical suitable acyclic glycosyl groups represented by formula IIA include -CH₂-O-CH₂CH₃, -CH(CH₃)-O-CH(CH₃₎₂, -CH₂-O-(CH₂)₂CH₃, -CH₂-O-(CH₂)₃-CH₃, -CH(CH₃)-O-CH₂CH(CH3)₂, -CH₂-O-(CH₂)₄-CH₃, -CH(CH₃)-O- CH(CH₃)-(CH₂)₃-CH₃, -CH₂-O-CH₂-CH(OCH₃)CH₃, -CH₂-O- CH(CH₂OH)-CH₃ or -CH(CH₃)-O-CH(CH₂OH)(CH₂)₃CH₃.

R_q which may be in the axial (a) position

(formula IIB) or equatorial (e) position (formula IID) and is preferably hydroxy, methoxy or acyloxy. R_t is preferably hydrogen, hydroxy, lower alkoxy, for example methoxy, or acyloxy, for example acetyloxy, butyryloxy or iso-valeryloxy. R_s and R_w may be in the axial or equatorial position. R_s is preferably hydrogen or methyl; R_w is preferably methyl.

The preferred glycosyl groups include the following α-L-glycosyl groups represented by formulas IIB, IIC and IID

wherein R_s and R_w are independently hydrogen or methyl and wherein R is hydroxy, lower alkoxy or lower acyloxy and R_t is hydrogen, hydroxy, lower alkoxy or acyloxy:

as well as 4-epi derivatives of all of the above glycosyl groups .

The corresponding β-L-glycos ide groups and α- or β-3-tetrahydropyranyl group , i . e . ,

The more preferred α -L - glycosyl groups of formula IIB, IIC, and IID are α-L-cladinosyl, 4-O-acyl-α-L-cladinosyl, α-L-digitoxsyl, 3-O-methyl-α-L-digitoxsyl, 3,4-di-O-acyl-α-L-digitoxsyl, 3,4-di-O-acyl-α-L-mycarosyl,4-O-acyl-α-L-oleandrosyl, and 3-tetrahydropyranyl.

The α-L-cladinosyl group may be obtained by acid cleavage of erythromycin-A [See Example 1(a)]. The preparations of α-L-digitoxose and 3-O-methyl-α-L-digitoxose are disclosed by J.S. Brimacombe et al. in J. Chem. Soc., Perkin Trans I, 1982, pp 2583-2587; and the preparations of α-L- and α-L-3-epi-mycarose, α-L-oleandrose, α-L-olivose, α-L-cladinose, α-L-digitoxose and α-L-arcanose as well as the pentoses are disclosed in The Carbohydrates, Chemistry and Biochemistry, 1980, 2nd Edition (W. Pigman et al.. Editors), Chapter 17 (N.R. Williams et al.), pp 761-798 Academic Press, New York.

Typical suitable starting materials for preparation of the compounds of this invention include any of the known 16-membered macrolides having a free or potentially free hydroxy group at the C-3 carbon as defined in formula I and which may possess other reactive tertiary, secondary or primary hydroxy groups suitably protected as described hereinafter. Typical suitable starting materials useful in preparation of the compounds of the present invention include the following known antibiotics or those that are readily preparable from known antibiotics. The preparation of desmycosin and that of tylosln are described by R. L. Hamill et al. in U.S. Patent No. 3,178,341. The preparation of macrocin and that of lactenocin are described by R. L. Hamill et al.. in U.S. Patent No. 3,326,759. Cirramycin A₁ is prepared as described by H. Koshiyama et al., J. Antibiotics Ser. A16, 59-66 (1963) and S. Nash et al . in U.S. Patent No. 4,252,898. Antibiotic M-4365 G₂ (repromicin) can be prepared by the method described by T. Furumai et al. in J. Antibiotics, 30, 443-449 (1977) or as described by A. K. Ganguly in U.S. Patent No. 3,975,372. The preparation of 9-dihydrodesmycosin (dihydrodesmycosin) is described by E.H. Massey in U.S. Patent No. 3,769,273. 9- Dihydrolactenocin is prepared in an analogous manner. Rosaramicin can be prepared as described by M. J. Weinstein et al. in U.S. Patent No. 4,234, 690. The preparation of 12,13-deoxo-12,13-dehydrorosaramicin (M-4365A₂) and that of 20-deoxo-20-dihydro-12,13-deoxo-12,1,-dehydrorosaramicin are described in Examples 1 and 28, respectively, of U.S. Patent No. 4,056,616. The preparation of 23-demycinosyltylosin (DMT), 20-dihydro-DMT, 5-O-mycaminosyltylonolide (OMT) and of 20-dihydro-OMT are described in U.S. Patent No. 4,321,361. The preparation of 23-deoxy-5-O-mycaminosyltylonolide (DOMT), 23-de (mycinosyloxy)tylosin (DMOT), 20-dihydrodesmycosin, and of 20-dihydrolactenocin are described in U.S. Patent No. 4,357,325.

The preparation of 20-deoxo-20-dihydroDMOT is described in U.S. Patent No. 4,528,369. The production of 16-membered macrolide antibiotics CP-56,064 and CP 56,063 by fermentation of Streptomyces albus is described in U.S. Patent No. 4,454,314. Other typical suitable starting materials may be prepared from the antibiotics listed hereinabove by use of known synthetic techniques. Thus, for example, the formyl group in desmycosin, DMOT, tylosin, 12,13-deoxo-12,13-dehydrorosaramicin or DMT can be replaced by hydrogen by use of tris (triphenylphosphine) rhodium chloride, in accordance with the procedure described in U.S. Patent No. 4,345,069, to give the corresponding 19-deformyl derivative, e.g. 19-deformyldesmycosin. In addition, epoxidation of the 12,13 double bond in for example, tylosin, DMT, 19-deformyl DMT, DMOT or 19-deformyl DMOT may be performed using m-chloroperbenzoic acid as described in U.S. Patent No. 4,477,443 (Examples 58-61) to give the corresponding 12,13-oxo derivative, e.g. 12,13-oxotylosin, 12,13-oxo DMT, 19-deformyl-12,13- oxoDMT, 12,13-oxo DMOT and 19-deformyl-12,13-oxoDMOT. The production of 12,13-oxo DMOT (antibiotic M119a) by fermentation of alkalophilic Actinomycetes is disclosed by H. Tanaba et al. Paper #1150 25th ICAAC, Minneapolis, MN 29 Sept. to 2 Oct. 1985.

Additional suitable starting materials useful for preparation of the compounds of this invention may be obtained by modification of the suitable starting materials hereinabove such as 19-deformyl DMT by well known techniques to convert the free hydroxy group at the 23-carbon in such compounds into compounds wherein the 23-carbon is attached to acyloxy-N,N-di(lower alkyl)amino, lower alkoxycarbonyloxy, aralkoxycarbonyloxy, N-loweralkylaminocarbonyloxy or N-aralkylaminocarbonyloxy.

Compounds of the present invention are made by reacting a compound having the formula

wherein X, Y, Z and R² are as previously defined with a compound of the formula

L - R₁

wherein L is a leaving group and R₁ is as previously defined, wherein any reactive groups are protected, if necessary or desired, followed if necessary or desired by one or more of the following steps:

(i) removal of any protecting group, (ii) conversion of the compound so formed to a different compound of formula I, and/or

(iii) formation of a pharmaceutically acceptable acid addition salt of the compound of formula I.

The preferred leaving group, L, is pyridyl-2-thio. The Glycosylation Reaction The glycosyl groups are attached to the free hydroxyl group at the C-3 carbon of the 16-membered macrolide starting materials by use of the procedures known in the art. For example, the procedure of Tatsuta, Carb. Research 1977, 54 , p. 85 or of R. B. Woodward et al., J. Am. Chem. Soc. 1981, 103, p. 3215 may be used.

Generally, a suitably protected glycosyl group, e.g., l-deoxy-1-(pyridyl-2-thio)-α and/or β-L-glycoside such as the 1-S-pyridyl derivative of L-cladinose is reacted with a 16-membered macrolide having a free hydroxyl group at the C-3 carbon (and with other reactive tertiary, secondary and/or primary hydroxyl groups suitably protected) in the presence of anhydrous silver perchlorate or anhydrous silver trifluoromethylsulfonate in an anhydrous aprotic solvent such as acetonitrile. Reaction temperatures of 20-25°C for 20-30 hours are conveniently used.

Prior to the glycosylation of the free hydroxy group at the C-3 carbon, any other free hydroxy groups are conveniently protected as acyl derivatives by use of (C₁-C₅)alkanoic anhydrides, such as, acetic anhydride in the presence of added base such as pyridine, or as the silyl ethers. Standard deprotection techniques which are well known are used to remove the acyl or silyl protecting groups. When the macrolide has a lactone moiety which is sensitive to base-catalyzed ring opening during the deprotecting procedures used to remove, for example, the acyl protecting groups, more labile acyl protecting groups such as aryloxyacyl, haloacetyl, alkoxyacetyl, formyl or haloalkoxycarbonyl may be used. Since very mild basic conditions are employed to remove these more labile acyl groups, the lactone moiety is not adversely affected. In this manner, more labile protecting groups such as phenoxyacetyl may be used for protecting the hydroxyl groups in the glycoside group. For example, phenoxyacetyl chloride in the presence of pyridine is reacted with L-digitoxose to form 1,3,4-tri- O-phenoxyacetyl-α- and -β-L-digitoxose. The 1-O- phenoxyacetyl group is removed by treatment at ambient temperatures, e.g., 25°C with aqueous HC1 e.g. 0. IN HCl The product so formed is reacted with 2,2- dipyridyldisulfide in the presence of tri-n- butylphosphine to give 3,4-di-O-phenoxyacetyl-1-deoxy-1- (pyridyl-2-thio)-α and/or β-L-digitoxose.

Exemplary of the preparation of compounds of the present invention is the following process for the preparation of 3-0_- ct-and/or- β-L-cladinosyl-12,13-deoxo- 12,13-dehydrorosaramicin and the corresponding 19- deformyl and 20-deoxo-20-dihydro compounds of formula la wherein Y=CH0, H and CH₃, respectively.

As illustrated in the above schematic, 12,13-deoxo-12,13-dehydrorosaramicin or the corresponding 19-deformyl- and

20-deoxo-20-dihydro derivatives represented by formulas

Illa-c wherein Y=CHO, H and CH₃, respectively, is acylated at the hydroxy on the 2' carbon by use of a lower alkanoic acid anhydride, (R'CO)₂O, normally acetic anhydride in acetone at 25°C to form the 2'-O-acyl 12,13-deoxo-12,13-dehydrorosaramicin represented by formula

IVa. Compound IVa is reacted with 4-O-acyl-1-deoxy-1- (pyridyl-2-thio)-α- and/or -β-L-cladinoside in the presence of anhydrous silver perchlorate or anhydrous silver trifluoromethylsulfonate in anhydrous acetonitrile at 25°C for 20 hours to provide the O-(4'-O-acyl-α-L-cladinosyl)-(1→3)-12,13-dehydro-12,13-deoxorosaramicin, compound Va (or the corresponding deformyl or 20-deoxo- 20-dihydro rosaramicin derivatives). The acyl groups in compound Va-c are removed from the 2'' hydroxyl group in the desosaminyl sugar and the 4'-hydroxyl group in the cladinosyl sugar by treating compound Va-c with an organic trisubstituted nitrogen base for example, 1,8-diazabicyclo [5.4.0] undec-7-ene (DBU) and a lower alkanol, e.g., methanol to give compounds of formula Ia:Y=CHO, lb:

Y=H or Ic:Y=CH₃ and X=Z=H.

As used herein, the term "organic trisubstituted nitrogen base" refers to acyclic tertiary amines, pyridine and lower alkyl substituted pyridines and bicyclic tertiary amines. Typical suitable acyclic tertiary aliphatic amines include tri(lower alkyl) amines such as trimethylamine, triethylamine, tri-n-propylamine and dimethyl-sec-butylamine. Triethylamine is the preferred acyclic tertiary amine. Typical suitable substituted pyridines include 2-, 3- and 4-methylpyridine.

Typical suitable bicyclic tertiary amines include 1,5-diazabicyclo[4.4.0]non-5-ene, hereinafter "DBN" and 1,8- diazabicyclo[5.4.0]undec-7-ene, hereinafter "DBU". The term "lower alkanol" refers to straight and branched-chain alcohols of one to six carbons such as methanol, ethanol, n- and iso-propanol. Methanol is preferred.

The 4-O-acylcladinosyl derivatives (Vla-c) of the compounds of formulas Ia-c are prepared by selectively removing the acyl group from the 2'' position of the desosaminyl sugar by treating compounds Va-c with a lower alkanol, normally methanol, at 25°C for 16 hours.

Using procedures similar to those outlined for the preparation of 3-O-α-glycosyl 16-membered macrolide antibacterials of this invention, the 3-O-β-glycosyl 16- membered macrolide antibacterials of this invention wherein the glycosyl group, R₁, is represented by formula II may be prepared as described in Example 20.

The 3-O-glycosyl 16-membered macrolide antibacterials of this invention wherein the glycosyl group, R₁, is represented by the formula IIA may be prepared as described in Example 18.

This invention also relates to a pharmaceutical composition comprising a compound of the present invention or its pharmaceutically acceptable acid addition salts in admixture with a pharmaceutically acceptable carrier.

The compounds of the present invention are capable of forming pharmaceutically acceptable acid addition salts with inorganic and organic acids. The term "pharmaceutically acceptable acid addition salts" means those salts that do not exhibit toxic manifestations at normal therapeutic doses. Exemplary of such salts are those formed by reaction of the compounds of this invention with acids such as hydrochloric, sulfuric, phosphoric, citric, acetic, propionic, tartaric, maleic, benzoic, cyclopropylcarboxylic, adamantylcarboxylic, lauryl sulfonic, glucoheptonic, stearic, lactobionic and the like. Pharmaceutically acceptable acid addition salts may be prepared by methods generally used in the art such as by adding a stoichiometric amount of acid to a solution of a compound of the invention in an inert organic solvent and isolating the salt by art known methods such as precipitation of the salt with a solvent wherein the salt is not appreciably soluble, e.g. diethyl ether. An inert organic solvent is one which does not react with the antibacterial, the acid or the salt under conditions of the reaction.

Typical pharmaceutically acceptable carriers suitable for use in the formulations described are exemplified by sugars such as lactose, sucrose, mannitol and sorbitol; starches such as corn starch, tapioca starch and potato starch; cellulose and derivatives such as sodium carboxymethyl cellulose, ethyl cellulose and methyl cellulose; calcium phosphates such as dicalcium phosphate and tricalcium phosphate; sodium sulfate; calcium sulfate; polyvinyl pyrrolidone; polyvinyl alcohol; stearic acid; alkaline earth metal stearates such, as magnesium stearate; vegetable oils such as peanut oil, cottonseed oil, sesame oil, olive oil and corn oil; non-ionic, cationic and anionic surfactants, ethylene glycol polymers; betacyclodextrin; fatty acids, hydrolyzed cereal solids; water, polyalkylene glycols; gums; and petroleum ; as well as other non-toxic compatible fillers, binders, and lubricants commonly used in pharmaceutical formulations. The compositions may also contain preservatives, areosol propellants and coloring, thickening, suspending, dispensing, emulsifying, wetting, stabilizing and buffering agents.

This invention also embraces a method of eliciting an antibacterial effect against susceptible bacterial infections which comprises administering to an animal, preferably a warm-blooded animal such as man having a susceptible bacterial infection an antibacterially effective amount of a compound of formula I or a pharmaceutical composition thereof.

In order to elicit an antibacterial effect against a susceptible bacterial infection, the compounds of this invention may be administered orally, intramuscularly, topically or intraveneously. Administration may be effected by any of the conventional methods, i.e., by the use of tablets, capsules, and suspensions, solutions, creams, ointments or injectables. Each of the dosage forms can be formulated utilizing non-toxic pharmaceutically acceptable exc ipients conventionally known in the art. The compounds of this invention are preferably administered intravenously at doses of from about 5 to about 50 mg per kg per day, preferably from about 15 to about 30 mg per kg per day, in single or divided doses. The compounds of this invention may also be administeredorally at doses of from about 15 mg/kg to 50 mg/kg or subcutaneously at doses of about 15 mg/kg to 30 mg/kg.

The compounds of this invention elicit an antibacterial effect against a wide variety of bacterial species, but are generally more active against strains of Gram-positive bacteria. Exemplary of the bacteria against which the compounds of this invention are active are various strains of Staphylococci and Streptococci.

The compounds of the invention have enhanced (IV) serum levels and a similar spectrum of antibacterial activity to that of the corresponding parent 16-membered macrolide having a free C-3 hydroxyl group. The compounds are also active against erythromycin-resistant strains of Staphylococci and methicillin-susceptible and methicillin-resistant strains of Staphylococci.

Specifically,O -(α-L-cladinosyl)-(1→3)-12,13-dihydro-12,13-deoxorosaramicin, a compound of this invention compared to 12,13-dehydro-12,13-deoxorosaramicin is slightly less active against erythromycin-resistant strains of Staphylococci and against sensitive Gram-positive bacteria, but equal to, or slightly more active against various strains of Streptococci.

The antibacterial activity of the compounds of this invention is determined by testing against a variety of pathogens using standard antibacterial dilution assays in Mueller-Hinton agar, the activity being expressed as the Minimum Inhibitory Concentration (MIC, meg./ml., 24 hours). The geometric mean MIC's of the compounds of this invention are in the range of about 0.088 to 27.

Most importantly, the compounds of this invention are active antibacterial agents which afford good serum levels at the antibacterially effective dosages provided hereinabove. EXAMPLE 1 (starting materials)

4-O-Acetyl-1-Deoxy-1-(Pyridyl-2-thio)-α- and -β-L-Cladinoside

(a) L-Cladinose

Erythromycin A (Merck Index, 10th Edition Entry No. 3624) (50g) was dissolved in IN aqueous hydrochloric acid (70 mL) and water (500 mL) and the mixture subjected to liquid-liquid extraction using diethyl ether for 99 h. The ether extract was evaporated to dryness to give L-cladinose (11.7g, 97%) as a colorless viscous oil.

(b) 1,4-Di-O-acetyl-β-L-cladinose L-Cladinose (16.23g) and acetic anhydride (66.7 mL) were dissolved in dry pyridine (133 mL) and the mixture was allowed to remain at 25°C for 18 h. The mixture was evaporated to dryness and the residue was azeotroped with toluene. The product was chromatographed on a silica gel column (45×5 cm) using 3% ethyl acetate in chloroform (v/v) as the eluant to give 1,4-di-O-acetyl-β-L-cladinose (19.2g, 80%) as a colorless solid (Anal, found: C,55.79; H, 7.91%; C₁₂H₂₀O₆ requires: C, 55.37; H, 7.74%); MS: 201 (MH⁺-CH₃COO); Rotation: [α]_D ²⁶ -41.3°(CHCl₃); IR: v_max (CDCl₃) 1750, 1735, 1238, 1050 cm^-1; 'H-NMR: δ_H (CDCl₃) 1.17 (3H,d,J_5ax,6-CH₃7H_z, 6-CH₃), 1.17 (3H,s,3-CH₃), 1.57 (1H,dd,J_1ax 2ax 10Hz,

J_2ax,2eq 13Hz H_2ax), 2.12 (3H,s,1-OCOCH₃), 2.15 (3H,s,4-OCOCH₃), 2.28 (1H,dd,J_1ax,2eq 2Hz,J_{2ax, 2eq} 13Hz,H_2eq 3.32 (3H,s,3-OCH₃), 4.10 (1H,dq,J_5ax,6-CH₃ 7Hz, J_4ax,5ax 10Hz, H_5ax), 4.68 (1H.d,J_4ax,5ax 10Hz,H_4ax) and 5.92

(1H,dd,J_1ax,2ax 10Hz, J_1ax,2eq 2Hz, H_1ax). (c) 4-O-Acetyl-α- and -β-L-cladinose

1,4-Di-O-actyl-β-L-cladinose (2.18g) was dissolved in 0.1N aqueous hydrochloric acid (245 mL) and the mixture was allowed to remain at 25°C for 1 h. The mixture was extracted with diethyl ether and the ether layer was retained. The aqueous acid layer was neutralized and extracted with dichloromethane. The latter was combined with the ether extract and dried (MgSO4), filtered and evaporated to dryness to give 4-O-acetyl-α- and β-L-cladinose (1.86g, 100%) as a colorless gum that was used without further purification.

(d) 4-O-Acetyl-1-deoxy-1-(pyridyl-2-thio)-α- and-β-L- cladinoside

4-O-Acetyl-L-cladinose (1.84g) was dissolved in dry dichloromethane (25 mL) and the solution was cooled to 13°C. After 30 minutes a chilled solution of 2,2'-dipyridyldisulphide (Aldrithiol-2) (2.8g) and tri-n-butylphosphine (3.45g) in dry dichloromethane (30 mL) was added in one portion. The mixture was allowed to remain at 13°C under dry argon for 19 h. The solution was evaporated to dryness and the residue chromatographed twice on silica gel columns (20×5 cm) using first 4%ethyl acetate in chloroform and then 2% ethyl acetate in chloroform (v/v) as the eluant to give 4-O-acetyl-1-deoxy-1-(pyridyl-2-thio)-α-L-cladinoside (604 mg, 23%) as a colorless gum (Anal.: found: C, 58.15; H, 6.84; N, 4.54% C₁₅H₂₁NO₄S requires: C, 57.86; H, 6.80; N, 4.50%); MS: m/z 312 (MH⁺); Rotation: [α]_D ²⁶ -339.0° (CHCl₃); UV: λ_max (CF₃CH₂OH) 239 nm (ε9,029), 282 nm (ε5,122); IR: v_max (CDCl₃) 1730, 1580, 1418, 1238, 1063, 1045 cm^-1; ¹H-NMR: δ_H(CDCl₃) 1.12 (3H,d,J_5ax,6-CH₃ 7Hz, 6-CH₃), 1.20 (3H,s,3-CH₃), 2.15 (1H,dd,J_1eq,_2ax 5Hz,

J_2eq,2ax15Hz,H_2ax), 2.17 (3H,s,4-OCOCH₃), 2.58 (1H,dd,J_1eq,2eq 2Hz, J_2eq,2ax 15Hz, H_2eq), 3.37 (3H,s,3- OCH₃), 4.53 (1H,dq,J_5ax,6-CH₃ 7Hz, J_4aX,5ax 10Hz, H_5ax) 4.74 (1H,d,J_4ax,5ax 10Hz, H_4ax), 6.38 ( 1E , dd, J _{1 e q , 2e q}

2Hz, J_1eq,2ax 5Hz, H_1eq), 7.00 (1H, m, 1-S-C₅H₄N(H₅)), 7.33 (1H,m, 1-S-C₅Η₄N(H₃)), 7.52 (1H, m, 1-S-C₅H₄(H₄)) and 8.51 (1H, m, 1-S-C₅H₄( H₆)), and 4-O-acetyl-1-deoxy-

1-(pyridyl-2-thio)-β-L-cladinoside (12) (1.02g, 39%) as a colourless gum (Anal.: found: C, 57.46; H, 6.86; N,

4.36. C₁₅H₂₁NO₄S requires: C, 57.86; H, 6.80; N, 4.50%);

MS: m/z 312 (MH⁺); Rotation: [α]_D ²⁶ -1.1° (CHCl₃); UV: λ_max (CF₃CH₂OH) 237 nm (ε7,814), 279 nm (ε4,585); IR: v_max (CDCl₃) 1737, 1580, 1418, 1238, 1072, 1046 cm^-1; ¹H- NMR: ^δH (CDCl₃) 1.16 (3H,d, ^J5ax,6-CH₃ 7Hz,6-CH₃), 1.19 (3H, s, 3-CH₃), 1.81 (1H, dd, J_1aX,2a_χ 11Hz, J_2eq,2ax 16Hz, H_2ax), 2.16 (3H, s, 4-OCOCH₃), 2.44(1H, dd,

J1_eq,2eq 2Hz, ^J2eq,2ax 16Hz, H_2eq)' 3.34 (3H' s, 3-OCH₃), 4.12 (1H, dq, ^J5ax,6-CH3 7Hz, J_4ax,5ax 10Hz, H_5ax)_, 4.73 (1H, d, J_4ax,5ax, 10Hz, H_4ax), 5.70 (1H, dd, J_1ax,2ax 11Hz, J_1ax,2eq 2Hz, H_1ax), 7.06 (1H, m, 1-S-C₅H₄N ( H₅)),

7.35 (1H, m, 1-S-C₅H₄N(H₃)), 7.56 (1H, m, 1-S-C₅H₄N(H₄)) and 8.42 (1H, m, 1-S-C₅H₄N(H₆)).

EXAMPLE 2

O-α-L-Cladinosyl-(1→3)-12,13-dehydro-12,13-deoxo¬rosaramicin

(a) 2'-O-Acetyl-12,13-dehydro-12,13-deoxorosaramicin

12,13-Dehydro-12,13-deoxorosaramicin (2g) and acetic anhydride (1 mL) were dissolved in dry acetone (100 mL) and the solution so formed was allowed to remain at 25°C for 19 h. The reaction mixture was evaporated to dryness and the residue was taken up in dichloromethane and washed with water having a pH equal to 10. The organic layer was dried ( MgSO₄ ) / f i ltered and evaporated to dryness. The residue was chromotographed on a silica gel column (60×2 cm) using 10% acetone in chloroform as the eluant to give 2'-O-acetyl-12,13-dehydro-12,13-deoxorosaramicin (1.79g, 83%) as a colorless amorphous solid (Anal.: found: C, 62.06; H, 8.34; N, 1.54%; C₃₃H₅₃NO₉ 0.2 CHCl₃ requires: C, 62.75; H, 8.46; N, 2.22%); MS: m/z 608 (MH⁺); Rotation: [α]_D ²⁶ -4.4°(CHCl₃; UV: λ_max (CF₃CH₂OH) 288 nm (ε19,165); IR: v_max (CDCl₃) 3530, 1740, 1723, 1675, 1593, 1248, 1060 cm^-1;¹H-NMR: ^δH (CDCl₃) 0.93 (3H,t,J16, 17-CH 7Hz, 17-CH3 ) , 0.96 (3H,d,J 7Hz, CH3), 1.08 (3H,d,J 7Hz, CH₃), 1.20 ( 3H,d,J,7Hz,CH₃), 1.22 (3H,d,J,7Hz,CH₃), 1.81 (3H,d,J12-CH₃ ,13 1Hz, 12-CH₃), 2.08 (3H,s,2'-OCOCH₃), 2.26 (6H,s,3'-N(CH₃)2), 4 . 25

(1H,d,J_1ax,2'ax 8Hz, H_1'ax), 5.66 ( 1E , dq ,J_{12-CH, 13} 1Hz'

J_13,14 10Hz, H₁₃), 6.30 (1H'd'J_10,11 16Hz, H₁₀), 7.31 (1H,d,J_10,11 16Hz, H₁₁ ) and 9.70 (1H,s,H₂₀).

(b) 2"-O-Acetyl-O-(4'-O-acetyl-α-L-cladinosyl)-(1→3 )-12,13-dehydro saramicin

2'-O-Acetyl-12,13-dehydro-12,13-deoxorosaramicin (1g) and 4-O-acetyl-1-deoxy-1-(pyridyl-2-thio)-α- and-β-L-cladinoside (from Example 1(d)) (2.83g) were dissolved in dry acetonitrile (60 mL) under dry argon. A solution of anhydrous silver perchlorate (2.22g) in dry acetonitrile (61 mL) was added and the mixture was stirred under" dry argon at 25°C for 18 h. The mixture was evaporated to dryness and the residue was taken up in dichloromethane and washed with water, the pH being adjusted to 10. The organic layer was dried (MgSO₄), filtered and evaporated to dryness. The residue was chromatographed on a silica gel column (30×5 cm) using ethyl acetate as the eluant to give unreacted 2 ' - O-acetyl-12,13-dehydro-12,13-deoxorosaramicin (460 mg., 46%) and 2''-O-acetyl-O-(4'-O-acetyl-α-L-cladinosyl)- (1→3)-12,13-dehydro-12,13-deoxorosaramicin (718 mg., 54%) as a colorless amorphous solid (Anal.: found: C, 62.30; H, 8.27; N, 1.53%; C₄₃H₆₉NO₁₃. 0.2 CHCl₃ requires: C, 62.08; H, 8.36; N, 1.68%); MS: m/z 808 (MH⁺); Rotation: [α]_D ²⁶ -46.5° (CHCl₃); UV: λ_maχ (CF₃CH₂OH) 287 nm (ε17,964); IR: v_maχ (CDCl₃) 1737, 1728, 1673, 1590, 1242, 1050 cm^-1; ¹H-NMR: δ_H (CDCI₃) 0.89 ( 3H, t, J16, 17-CH₃ 7Hz, 17-CH₃), 0.94 (3H,d,J 7Hz, CH₃), 1.04 (3H,s,3'-CH₃), 1.05 (3H,d,J 7Hz,CH₃), 1.06 (3H,d,J 7Hz, CH₃), 1.18 (3H,d,J 7Hz, CH₃), 1.20 (3H,d,J 7Hz, CH₃), 1.79 ( 3H,d,J12-CH₃ 13 1Hz, 12-CH₃), 2.08 ( 3H,s,2''-OCOCH₃), 2.11 (3H,s,4'- OCOCH₃), 2.29 (6H,s,3''-N(CH₃)₂), 3.17 ( 3H,s,3'-OCH₃), 4.33 (1H,d,J_{1''axf2' 'ax} 8Hz, H_1''ax), 4.66 (1H,d,J_4,ax/5'ax 10HZ, H_4'aχ), 4.74 (1H,dd, J₁''ax ,2''ax

8Hz, J_2''ax,3''ax 10Hz, H_2"ax), 4^.99 (1H,dd,J_1'eq,2'eq 1.5Hz, J_{1 'eq,2'ax} 4Hz' H_1'eq)' 5.64 (1H,dq,

^J12-CH₃,13 1 H z , J_13,14 10Hz, H₁₃), 6.25 (1H,d,J_10,11 16Hz, H₁₀), 7.28 (1H,d,J_10,11 16Hz, H_{1 1} ) and 9.71

(1H,s,H₂₀).

(c) O-α-L-Cladinosyl-(1→3)-12,13-dehydro-12,13-deoxorosaramicin

2 ' ' -O-Acetyl-O - ( 4 ' -O-acetyl- α-L -cladinosyl ) - (1→3)-12,13-dehydro-12,13-deoxorosaramicin (567 mg) was dissolved in a 0.57% (w/v) solution of 1,8-diazabicyclo

[5.4.0] undec-7-ene (0.1065 mL) in methanol (19 mL) and the solution was stirred at 25°C under argon for 43 h. The mixture was evaporated to dryness and the residue was taken up in dichloromethane and washed with water, the pH being adjusted to 10. The organic layer was dried (MgSO₄), filtered and evaporated to dryness. The residue was chromotographed on a silica gel column (15×5 cm) using 2.5% methanol in chloroform as the eluant to giveO-α-L-cladinosyl-(1→3)-12,13-dehydro-12,13-deoxorosaramicin (265 mg., 52%) as a colourless amorphous solid (Anal.: found: C, 64.19; H, 9.46; N, 2.01%; C₃₉H₆₅NO₁₁ requires: C, 64.71; H, 9.05; N, 1.93%); MS: m/z 724 (MH⁺); Rotation: [α]_D ²⁶-51.0° (CHCl₃); UV: λ_maχ (CH₃OH) 282 nm (ε19,623); IR: v_maχ (CDCl₃) 3540, 3440, 1728, 1674,

1590, 1160, 1050 cm.^-1; ¹H-NMR: % (CDCl₃) 0.90

(3H,t,J16,17-CH₃ 7Hz, 17-CH₃), 1.05 (3H,d,J 7Hz, CH₃),

1.11 (3H,d,J 7Hz, CH₃), 1.15 (3H,s, 3'-CH₃), 1.17 (3H,d,J

7Hz, CH₃), 1.19 (3H,d,J 7Hz, CH₃), 1.20 (3H,d,J 7Hz,

CH3), 1.79 (3H,d,J12-CH₃,13 1Hz, 12-CH₃), 2.28 (6H,s,3''- N(CH₃)₂), 3.12 (3H,s,3'-OCH₃), 4.24 (1H,d,J_{1''ax,2' 'ax}

8Hz, H_1''ax), 4.67 (1H,m,H₁₅), 4.94 (1H,dd, J_1'eq,2'eq

1Hz' J_1'eq,2'ax 4Hz, H_1'eq), 5'67 (1H,dq , J12-CH₃,13 1Hz, J_{13 14} 10Hz, H₁₃), 6.24 (1H,d,J_{10 ,11} 16Hz, H₁₀), 7.33

(1H,d,J_{10 11} 16Hz, E₁₁) and 9.75 (1H,s,H₂₀).

EXAMPLE 3

O-α-L-Cladinosyl-(1→3)-12,13-dehydro-12,13,20-dideoxo-20- dihydrorosaramicin

(a) 2'-O-Acetyl-12,13-dehydro-12,13,20-dideoxo-20-dihydrorosaramicin 12,13-Dehydro-12,13,20-dideoxo-20-dihydrorosaramicin (prepared as described in Example 28 of US Patent 4,056,616) (4g) was dissolved in dry acetone (167 mL) and acetic anhydride (2.05 mL) was added. The mixture was stirred at 25°C for 18 h under dry argon. The solution was evaporated to dryness and the residue was taken up in dichloromethane and washed with water, the pH being adjusted to 10. The organic layer was dried (MgSO₄)/ filtered and evaporated to dryness. The residue was chromatographed on a silica gel column (60×2.5 cm) using 10% acetone in chloroform (v/v) as the eluant to give 2'-O-acetyl-12,13-dehydro-12,13,20-dideoxo-20-dihydrorosaramicin (3.7g, 85%) as a colourless amorphous solid (Anal.: found: C, 65.14; H, 9.04; N, 2.19%; C₃₃H₅₅NO₈.0.1 CHCl₃ requires: C, 65.43; H, 9.15; N, 2.31%); MS: m/z 594 (MH⁺); Rotation: [α]_D ²⁶+7.9° (CHCl₃); UV: λ_max (CF₃CH₀OH) 287 nm (ε21,705); IR: v_max (CDCl₃) 3310, 1737, 1725, 1677, 1592, 1250, 1188, 1060 cm^-1; ¹H- NMR: δ_H (CDCl₃) 0.85 (3H,t,J₁₆,17-CH₃ 7Hz, 17-CH₃), 0.94 (3H,t,J19/20-CH₃ 7Hz, 20-CH₃), 0.99 (3H,d,J. 7Hz, CH₃), 1.20 (3H,d,J 7Hz, CH₃), 1.08 (3H,d,J 7Hz, CH₃), 1.22 (3H,d,J 7Hz, CH₃), 1.79 (3H,d,J12-CH₃,13 1Hz, 12-CH₃), 2.09 (3H,s,2'-OCOCH₃), 2.27 ( 6H,s,3'-N(CH₃)₂), 3.46 (1H,m,H_5'ax), 3.72 (1H,dd,J_4,5 10Hz, J_5,6 1Hz, H₅), 4.33 (1H,d,J_1'ax,2,ax 8Hz, H_1'ax), 4.70 (1H,m,H₁₅), 4.80 (1H,dd,J_1'ax,_2'ax 8HZ, J_2'ax,3'ax 10HZ, H₂,_aχ), 5.64 (1H,dq,J₁₂_CH_{3 13} 1Hz, J_{13 ,14} 10Hz, H₁₃), 6.33 (1H,d,J_10,11 16Hz, H₁₀) and 7.32 (1H,d, J₁₀, ₁₁ 16Hz, H₁₁).

(b) 2''-O-Acetyl-O-(4'-O-acetyl-α-L-cladinosyl)-(1→3)- 12,13-dehydro-12,13,20-dideoxo-20-dihydrorosaramicin

2'-O-Acetyl-12,13-dehydro-12,13,20-dideoxo-20-dihydrorosaramicin (1.57g) and 4-O-acetyl-1-deoxy-1- (pyridyl-2-thio)-α and-β-L-cladinoside (Example 1(d)) (4.55g) were dissolved in dry acetonitrile (111 mL) under dry argon. A solution of anhydrous silver perchlorate (3.61g) in dry acetonitrile (100 mL) was added and the mixture was stirred under dry argon at 25°C for 26 h. The solution was evaporated to dryness and the residue was taken up in dichloromethane and washed with water, the pH being adjusted to 10. The organic layer was dried (MgSO₄), filtered and evaporated to dryness. The residue was chromatographed on a silica gel column (30×5 cm) using ethyl acetate as the eluant to give unreacted 2'-O-acetyl-12,13-dehydro-12,13,20-dideoxo-20-dihydrorosaramicin (471 mg., 30%) and 2''-O-acetyl-O-(4'-O-acetyl-α-L-cladinosyl)-(1→3)-12,13-dehydro-12,13,20-dideoxo-20-dihydrorosaramicin (1.31g, 63%) as a colorless amorphous solid (Anal.: found:. C, 60.51; H, 8.26; N, 1.22%; C₄₃H₇₁NO₁₂. 0.5 CHCl₃ requires: C, 60.50; H, 8.38; N, 1.64%); MS: m/z 794 (MH⁺); Rotation: [α]_D ²⁶ -91.2° (CHCl₃); UV: λ_maχ (CF₃CH₂OH) 286 nm (ε19,336), IR: v_maχ (CDCl₃) 1733, 1673, 1591, 1240, 1160, 1048 cm^-1; ¹H-NMR: fig (CDCl₃)t 0.89 ( 3H, t,J16 ,l7-CH₃ 7Hz, 17-CH₃),

0.90 (3H,t,J19,20-CH₃ 7Hz, 20-CH₃), 0.96 (3H,d,J4 , A-CH₃ 7H z , 4-CH₃), 1.03 (3H,d,J14,14-CH₃ 7Hz, 14-CH₃), 1.04 (3H,s,3'-CH₃), 1.09 (3H,d, J5'ax,6'-CH₃ 7Hz, 6'-CH₃), 1.18 (3H,d,J8,8-CH₃ 7Hz, 8-CH₃), 1.18 ( 3H,d, J5''ax,6''-CH₃ 7Hz, 6''-CH₃), 1.78 (3H,d,J12-CH₃,13 1Hz, 12-CH₃), 2.08 (3H,s,2''-OCOCH₃), 2.12 (3H,s,4'-OCOCH₃), 2.28 (6H,s,3''-N(CH₃)₂), 3.19 (3H,s,3'-OCH₃), 3.51 (1H,m,H5''ax), 3.69 (1H,dd,J_4,5 10Hz, J_5,6 1Hz, H₅), 4.36 (1H,d,J_{1' 'ax,2' 'ax} 8Hz, H_{1 ''ax}), 4.63 (1H,m,H₁₅), 4.65 (1H,d,J_4'ax,5,ax 10HZ, H_4'ax), 4.74 (1H,dd,J_{1' 'ax,2' 'ax} 8Hz, J_{2' 'ax,3' 'ax} 10HZ, H_{2' 'ax}), 4.85 (1H,dd,J_1'eq,2,eq 1.5Hz, J_{1 'eq,2''ax} 4Hz, H_1'eq), 5.59 (1H,dq,J12-CH₃, 13 1Hz, J_13,14 10Hz, H₁₃), 6.23 (1H,d,J_10,11 16Hz, H₁₀) and 7.23 (1H,d,J_10,11 16Hz, H₁₁). The proton assignments were confirmed by means of a 2D-NMR experiment at 400 MHz (δ_H/J correlation).

(c) O-α-L-Cladinosyl-(1→3)-12,13-dehydro-12,13,20-dideoxo-20-dihydrorosaramicin

2''-O-Acetyl-O-(4'-O-acetyl-α-L-cladinosyl-(1→3)-12,13-dehydro-12,13,20-dideoxo-20-dihydrorosaramicin (750 mg) and 1,8-diazabicyclo[5.4.0]undec-7-ene (0.705 mL) were dissolved in methanol (25 mL) and the solution was stirred at 25 °C for 20 h. The mixture was evaporated to dryness and the residue was taken up in dichloromethane and washed with water, the pH being adjusted to 10. The organic layer was dried (MgSO₄), filtered and evaporated to dryness. The residue was chromatographed on a silica gel column (60×2 cm) using 2% methanol in chloroform (v/v) as the eluant. The product was rechromatographed on a silica gel column (15×2 cm) using first chloroform (1 L) and then 2.5% increasing to 10% methanol in chloroform (v/v) as the eluant to give O- α-L-cladinosyl-(1→3)-12,13-dehydro-12,13,20-dideoxo-20- dihydrorosaramicin (428 mg., 64%) as a colorless amorphous solid. (Anal.: found: C, 61.55; H, 8.78; N, 1.56%; C₃₉Hg₇NO₁₀. 0.4 CHCl₃ requires: C, 61,82; H, 8.91; N, 1.85%); MS: m/z 710 (MH⁺); Rotation: [α]_D ²⁶ - 47.2° (CHCl₃); UV: λ_max (CH₃OH) 282 nm (ε20,594); IR: vmax (CDCl₃) 3550, 3440, 1730, 1670, 1590, 1160, 1055, 1020 cm^-1; ¹H-NMR: δ_H (CDCl₃) 0.89 (3H,t,J16,17-CH₃ 7Hz, 17-CH₃), 0.93 (3H,t,J19,20-CH₃, 7Hz, 20-CH₃), 1.04 (3H,d,J 7Hz, CH₃), 1.13 (3H,d,J 7Hz, CH₃), 1.15 (3H,s,3'- CH₃), 1.18 (3H,d,J 7Hz, CH₃), 1.20 (3H,d,J 7Hz, CH₃), 1.24 (3H,d,J 7Hz, CH₃), 1.78 (3H,d,J12-CH₃,13 1Hz, 12-CH₃), 2.28 (6H,s,3''-N(CH₃)₂), 3.14 (3H,s,3'-OCH₃), 4.26 (1H,d,J_{1''ax,2' 'ax} 8Hz, H_1''ax), 4.64 (1H,m,H₁₅), 4.81 (1H,dd,J_11eq,2,_eq 1HZ, J_1'eq,2,_ax 4Hz, H_1'eq), 5 .62 (1H,dq,J12-CH₃,13 1Hz, J_13,14 10Hz, H₁₃), 6.23 (1H,d,J_10,11 16Hz, H₁₀) and 7.28 (1H,d,J_10,11 16Hz, H₁₁).

EXAMPLE 4 (starting materials)

2'',4'',4'''-Tri-O-acetyl-O-(4'-O-acetyl-α-L-cladinosyl)-(1→3)-Desmycosin

(a) 2',4',4''-Tri-O-acetyldesmycos in

Desmycosin (Merck Index, Tenth Edition, p. 1405) (3.6g) and acetic anhydride (1.54 mL) were dissolved in dry pyridine (150 mL) and the mixture was allowed to remain at 25°C for 74 h. The mixture was evaporated to dryness and the residue was azeotroped with toluene. The residue was chromatographed on a silica gel column (30x5 cm) using 15% acetone in chloroform as the eluant to give 2',4',4''-tri-O-aceeyldesmycosin (1.91 g., 46%) as a colorless amorphous solid. (Anal.: found: C, 60.09; H, 8.08; N, 1.44%; C₄₅H₇₁NO₁₇ requires: C, 60.18;

H, 7.97; N, 1.56%); MS: m/z 898 (MH⁺); Rotation: [α]_D ²⁶ -3.1° (CHCl₃); UV: λ_max (CF₃CH₂OH) 286 nm (ε22,009); IR: v_max (CDCl₃) 3530, 1740, 1678, 1593, 1235, 1167, 1050 cm^-1 LH-NMR: δ_H (CDCl₃) 0.93 (3H,t,J16,17-CH₃ 7Hz, 17-CH₃), 0.97 (3H,d,J 7Hz, CH₃), 1.14 (3H,d,J 7Hz, CH₃), 1.18 (3H,d,J 7Hz, CH₃), 1.22 (3H,d,J 7Hz, CH₃), 1.80 (3H,d,J₁₂-CH₃,13 1Hz, 12-CH₃), 2.05 (3H,s,4'-OCOCH₃), 2.06 (3H,s,2'-OCOCH₃) 2.12 (3H,s,4''-OCOCH₃), 2.34 (6H,s,3'-N(CH₃)₂), 3.50 (3H,s,2''-OCH₃), 3.54 (3H,s,3"- OCH₃), 4.33 (1H,d,J_{1'ax 2'ax} 8Hz, H_{1 ' ax}) , 4.66 (1H,d,J_1''axf2''ax 8Hz/H_1''ax), 5.94 (1H,dq,J12-CH₃,13 1Hz, J_13,14 10Hz, H₁₃), 6.32 (1H,d,J_{10, 11} 16Hz, H₁₀), 7.36 (1H,d,J_10,11 16Hz, H₁₁), and 9.71 (1H,S,H₂₀).

(b) 2'',4'',4'',-Tri-O-acetyl-O-(4,-O-acetyl-α-L-cladinosyl)-(1→3)-desmycosin

2',4',4''-Tri-O-acetyldesmycosin (335 mg) and 4-O-acetyl-1-deoxy-1-(pyridyl-2-thio)-α- and -β-L-cladinoside (Example 1(d)) (953.5 mg) were dissolved in dry acetonitrile (20 mL) under dry argon. A solution of anhydrous silver perchlorate (750.5 mg) in dry acetonitrile (20.6 mL) was added and the mixture was stirred under dry argon at 25°C for 23 h. The mixture was evaporated to dryness and- the residue was taken up in dichloromethane and washed with water, the pH being adjusted to 10. The organic layer was dried (MgSO₄), filtered and evaporated to dryness. The residue was chromatographed on a silica gel column (60×2 cm) using 25% acetone in hexane (v/v) as the eluant. The product was rechromatographed on a silica gel column (60×2 cm) using 15% acetone in chloroform (v/v) as the eluant to give 2'',4'',4'''-tri-O-acetyl-O-(4'-O-acetyl- α-L-cladinosyl)-(1→3)-desmycosin (167 mg., 41%) as a colorless amorphous solid (Anal.: found: C, 60.11; H, 8.11; N, 1.26%; C₅₅H₈₇NO₂₁ requires: C, 60.15; H, 7.98; N, 1.28%); MS: m/z 1098 (MH⁺); Rotation: [α]_D ²⁶ -35.1° (CHCl₃); UV: λ_max (CF₃CH₂OH) 285 nm (ε22,465); IR: v_max 1740, 1680, 1595, 1240, 1168, 1050 cm^-1; 1H-NMR: δ_H (CDCl₃) 0.90 (3H,t,J16,l7-CH₃ 7Hz, 17-CH₃), 0.91 (3H,d,J 7Hz, CH₃), 1.07 (3H,s,3'-CH₃), 1.08 (3H,d,J 7Hz, CH₃), 1.13 (3H,d,J 7Hz, CH₃), 1.16 (3H,d,J 7Hz, CH₃), 1.20 (3H,d,J 7Hz, CH₃), 1.79 (3H,d,J12-CH₃ 13 1Hz, 12-CH₃), 2.04 (3H,s,4''-OCOCH₃), 2.05 (3H,s,2''-OCOCH₃), 2.12 (6H,s,4'-OCOCH₃ and 4'''-OCOCH₃), 2.37 (6H,s,3"- N(CH₃)₂), 3.19 (3H,s,3'-OCH₃), 3.47 (3H,s,2'''-OCH₃), 3.53 (3H,s,3'''-OCH₃), 4.46 (1H,d,J_1''ax,2''ax 8Hz,

H_{1' 'ax}), 4.62 (1H'd'J_{1'' 'ax,2"'ax} 8Hz, H_{1' ' 'ax}), 5.00 (1H.,dd,J_1'eq,2,eq 1Hz, J_1'eq,2'ax 4Hz, H_1'eq), 5.88

(1H,dq,J12-CH₃,13 1Hz, J_13,14 10Hz, H₁₃), 6.25

(1H,d,J_10,11 16Hz, H₁₀), 7.31 (1H,d,J_10,11 16Hz, H₁₁), and

9.70 (1H,s,H₂₀).

EXAMPLE 5

2'',4'',4'''-Tri-O-Acetyl-O-(4'-O-phenoxyacetyl-α-L-cladinosyl)-(1→3)-desycosin

(a) 1,4-Di-O-phenoxyacetyl-β-L-cladinose

(i) L-Cladinose (Example 1(a)) (2.85 g) and pyridine (19.65 mL) were dissolved in dry dichloromethane (84 mL) and the solution was cooled to 0°C under argon. A solution of phenoxyacetyl chloride (11.2 mL) in dry dichloromethane (84 mL) was added dropwise to the stirred solution over 1 h. The mixture was stirred at 0°C for 2.5 h. The mixture was diluted with dichloromethane and the washed with water, the pH being adjusted to 10. The organic layer was dried (MgSO₄), filtered and evaporated to dryness. The residue was azeotroped with toluene and chromatographed on a silica gel column (30×5 cm) using 1.5% acetone in chloroform (v/v) as the eluant to give 1,4-di-O-phenoxyacetyl-β-L-cladinose (3.3g, 46%) as a colourless gum (Anal.: found: C, 61.97; H, 6.20%; C₂₄H₂₈O₈ requires: C, 64-85; H, 6.35%); MS: m/z 293 (MH⁺-OCOCH₂OCgH₅); Rotation: [α]_D ²⁶ -26.0° (CHCl₃); UV: λ_maχ (CH₃OH) 206 nm (ε13,285), 260 nm (ε1,418), 266 nm (ε2,012), 273 nm (ε1,601); IR: v_maχ (CDCl₃) 1775, 1598, 1590, 1490, 1273, 1075, 1030 cm^-1; ¹H-NMR: δ_H (CDCl₃) 1.17 (3H,s,3-CH₃), 1.18 (3H,d,J5ax,6-CH₃ 7Hz, 6-CH₃), 1.63 dH,dd,J_1ax,2ax 10HZ, J_2eq,2ax 15Hz, H_2ax), 2.34 (1H,dd,J_1ax,2eq 4Hz, J_2eq,2ax 15HZ, H_2eq), 3.31 (3H,s,3-OCH₃), 4.20 (1H,dq,J_4ax,5ax 10Hz, J5ax,6-CH₃ 7Hz, H_5aχ), 4.66 (1H,d,J 16Hz, 1-OCOCH₂OC₆H₅), 4.71 (1H,d,J 16Hz, 1-OCOCH OCgHg) , 4.73 (lH,d,J 16Hz , 4-OCOCH₂OC_gH₅), 4.78 (lH,d,J 16Hz, 4-OCOCH₂OC₆H₅), 4.82 (1H,d,J_4ax,5aχ 10Hz, H_4aχ) , 6.08 ( 1H ,dd , J_{1 ax , 2eq} 4Hz , J_1ax , _2ax 10Hz , H_{1 ax} ) , 6.94 (4H,d,J 9Hz, 1- and 4-OCOCH₂OC₆H₅(H₂ and H₆)), 7.05 (2H,dd,J 9Hz, J 9Hz, 1- and 4-OCOCH₂OC₆H₅ (H₄)) and 7.35 (4H,dd,J 9Hz, J 9Hz, 1- and _.4- OCOCH₂OC₆H₅ (H₃ and H₅)).

(ii) L-Cladinose(10.82g) and pyridine (75.2 mL) were dissolved in dry dichloromethane (160 mL). A solution of phenoxyacetic anhydride (87.9 g) in dry dichloromethane (160 mL) was added dropwise to the stirred solution at 25 °C over 30 m. The mixture was diluted with dichloromethane and washed with water, the pH being adjusted to 10. The organic layer was dried (MgSO₄), filtered and evaporated to dryness. The residue was azeotroped with toluene and chromatographed by preparative HPLC on two silica gel cartridges using dichloromethane as- the eluant to give 1, 4-di-O-phenoxyacetyl-β-L-cladinose (17) (21.75g., 80%) which was identical with that prepared in 5(a) (i) above. (b) 4-O-Phenoxyacetyl-α- and-β-L-cladinose

1,4-Di-O-phenoxyacetyl-β-L-cladinose (63.35 g) was dissolved in acetonitrile (4.5 L) and 0. IN hydrochloric acid (4.158 L) was added and the mixture was stirred at 25°C for 18 h. The reaction mixture was neutralized to pH 7.3 and the acetonitrile was evaporated in vacuo. The resulting aqueous solution was extracted with diethyl ether (2×1.5 L) and then with dichloromethane (2×1.5 L). The combined organic extracts were evaporated to dryness and the residue was chromotographed on a preparative HPLC using two silica gel cartridges. The material was eluted using first dichloromethane and then 5% acetone in dichloromethane (v/v) to give 4-O-phenoxyacetyl-α- and β-L-cladinose (32 g., 72%) as a colorless gum that was used directly in the following experiment.

(c) 1-Deoxy-4-O-phenoxyacetyl-1-(pyridyl-2-thio-α- and -β-L-cladinoside

4-O-Phenoxyacetyl-α- and -β-L-cladinose (32g) were dissolved in dry dichloromethane (288 mL) and the solution was cooled to 14°C. A chilled solution of 2,2'-dipyridyldisulfide (Available from Aldrich Chemical Co. as Aldrithiol-2) (29.53g) and tri-n-butylphosphine (36.3 mL) in dry dichloromethane (288 mL) was added in one portion. The mixture was allowed to remain at 14°C under dry argon for 20 h. The mixture was washed with water, the pH being adjusted to 10. The organic layer was dried (MgSO₄), filtered and evaporated to dryness. The residue was chromatographed on a preparative HPLC using two silica gel cartridges. The material was eluted first with hexane (4 L.), then with 25% dichloromethane in hexane (4 L.), dichloromethane (4 L.) and finally 2% acetone in dichlormethane (4 L.) (v/v), to give a mixture of 1-deoxy-4-O-phenoxyacetyl-1-(pyridyl-2-thio)-α-and β-L-cladinoside (36.7 g., 88%) (49% α; 39% β). An aliquot was rechromatographed on a silica gel column (20x5 cm) using dichloromethane and then 0.5% acetone in dichlormethane (v/v) as the eluant to give from the more polar fractions, the pure β-anomer as a colorless solid; m.p. 74.5-79°C, (Anal.: found: C, 62.28; H, 6.26; N, 3.82; S, 7.72%. C₂₁H₂₅NO₅S requires: C, 62.51; H, 6.25; N, 3.47; S, 7.95%); MS: m/z 404 (MH⁺); Rotation: [α]_D ²⁶ +13.9° (CHCl₃); UV: λ_max (CF₃CH₂OH) 237 nm (ε7,991), 268 nm (ε4,479), 274 nm (ε5,258), 280 nm (ε4,883); IR: v_maχ (CDC1₃) 1760, 1734, 1596, 1572, 1190,

1065, 1005 cm^-1; ¹H-NMR: δ_H (CDCl₃) 1.16 (3H,d,J_5ax,6- CH₃ 7Hz, 6-CH₃), 1.18 (3H,s,3-CH₃), 1.86 (lH,dd,_J1ax,2ax 1 2Hz , J2_eq,2ax 15Hz, H_2ax), 2.44 (1H'dd'J_1ax,2eq 3Hz,

J_2eq,2ax 15Hz, H_2eq), 3.32 (3H's,3-OCH₃), 4.18 (1H,dq,J5ax,6-CH₃ 7Hz, J4aXf5ax 10HZ, H5ax), 4.74 (1H,d,J

16Hz, 4-OCOCH₂OC₆H₅), 4.78 (1H,d,J 16Hz, 4-OCOCH₂OC₆H₅), 4.86 (1H,d,J_4ax,5ax 10HZ, H_4ax), 5.74 (1H,dd,J_1ax,2eq

3Hz, ^J1ax,2ax 12Hz, H_1ax), 6.94 (2H,d,J 9Hz, 4-OCOCH₂OC₆H₅ (H₂ and H₅)), 7.03 (1H,dd,J 9Hz, J 9Hz, 4-OCOCH₂OC₆H₅ (H₄), 7.03 (1H,m,1-S-C₄H₄N(H₅)), 7. 32 (2H,dd,J 9Hz, J 9Hz, 4-OCOCH₂OC₆H₅ (C₂ and C₅)), 7.35 (1H,m,1-S-C₅H₄N(H₃)), 7.58 (1H,ddd,J_3,4=J_4,5=9Hz', J_{4, 6} 2.5Hz, 1-S-C₅H₄N(H₄)) and 8.48 (1H,m, 1-S-C₅H₄N(H₆)). The less polar fractions were combined and rechromatographed on a silica gel column (15×5 cm) using 2.5% acetone in hexane as the eluant to give the pure ct-anomer as a colorless solid, m.p. 131-133.5°C, (Anal.: found: C, 62.69; H, 6.29; N, 3.32; S, 8.18%. C₂₁H₂₅NO₅S requires: C, 62.51; H, 6.25; N, 3.47; S, 7.95%), MS: m/z 404 (MH⁺); Rotation: [α]_D ²⁶ -272.1° (CHCl₃); UV: λ_maχ (CF₃CH₂OH) 237 nm (εl5,737), 268 nm (ε8,675), 274 nm (ε10,067), 281 nm (ε9,180); IR: v_maχ (CDCl₃) 1760, 1595, 1575, 1190, 1063 cm^-1; ¹H-NMR; δ_H (CDCl₃) 1.13 (3H,d,J5aX,6-CH₃ 7Hz, 6-CH₃), 1.18 (3H,s,3-CH₃), 2.21 (1H,dd,J_1eq,2ax 6Hz, J_2eq,2ax 15HZ, H_2ax), 2.50 (1H,dd,J_1eq,2eq 1Hz, J_2eq,2ax 15Hz, H_2eq)' 3.34 (3H,s,3- OCH₃), 4.53 dH,dq,J_{4 ax , 5ax} 10Hz, J5ax,6-CH₃ 7Hz, H_5ax), 4.75 (1H,d,J 16Hz, 4-OCOCH₂OC₆H₅, 4.79 (1H,d,J 16Hz, 4- OCOCH₂OC₆H₅), 4.86 (1H,d,J_4ax,5ax 10Hz, H_4ax), 6.44

(1H,dd,J_1eq,2eq 1Hz, J_1eq,2ax 6Hz, H_1eq), 6.96 (2H,d,J 9Hz, 4-OCOCH₂OC₆H₅ (H₂ and H₆)), 7.06 (1H,dd,J 9Hz J 9Hz, 4-OCOCH₂OC₆H₅ (H₄)), 7.06 (1H,m,1-S-C₅H₄ (H₅)), 7.34 (2H,dd,J 9Hz, J9Hz, 4-OCOCH₂OC₆H₅ (H₃ and H₅)), 7.34 (1H,m,1-S-C₅H₄N(H₃)), 7.56 (1H,ddd,J_3,4=J_4,5=9Hz, J_4,6 2.5Hz, 1-S-C₅H₄N(H₄)) and 8.52 (1H,m,1-S-C₅H₄N(H₆)).

(d) 21',4'',4'''-Tri-O-acetyl-O-(4'-O-phenoxyacetyl-α-L- cladinosyl)-(1→3)-desmycosin

2'4',4''-Tri-O-acetyldesmycosin (Example 4(a)) (2.5 g.) and 1-deoxy-4-O-phenoxyacetyl-1-(pyridyl-2- thio)-α- and-β-L-cladinoside (Example 5(c)) (6.2 g.) were added to a solution of anhydrous silver trifluoromethanesulphonate (4.63 g) in dry acetonitrile (100 mL) and the mixture was stirred under dry argon at 25°C for 20 h. The mixture was evaporated to dryness and the residue was taken up in dichlormethane and washed with water, the pH being adjusted to 10. The organic layer was dried (MgSO₄), filtered and evaporated to dryness. The residue was chromatographed on a silica gel column (15×5 cm) using 11% acetone in hexane (v/v) as the eluant to give two partially purified cuts of the product. Each was rechromatographed on a silica gel column (30×2.5 cm us ing 20% ethyl acetate in dichloromethane (v/v) to give a combined pure sample of 2'',4'',4'''-tri-O-acetyl-O-(4'-O-phenoxyacetyl-α-L-cladinosyl)-(1→3)-desmycosin (1.99 g., 60%) as a colorless amorphous solid (Anal.: found: C, 61.34; H, 7.84; N, 0.88%; C₆₁H₉₁NO₂₂ requires: C, 61.55; H, 7.71; N, 1.18%), MS: m/z 1190 ( MH⁺); Rotation: [α]_D ²⁶ -30.0° (CHCl₃); UV: λ_max (CF₃CH₂OH) 284 nm (ε22,451), IR: v_max (CDCl₃) 1740, 1675, 1590, 1230, 1168, 1045 cm^-1; ¹H-NMR: δ_H (CDCl₃), 0.89 (3H,t,J_16,17_CH₃ 7Hz, 17-CH₃), 0.92 (3H,d,J 7Hz, CH₃), 1.05 (3H,s,3'- CH₃), 1.10 (3H,d,J 7Hz, CH₃), 1.12 (3H,d,J 7Hz, CH₃), 1.17 (3H,d,J 7Hz, CH₃), 1.21 (3H,d,J 7Hz, CH₃), 1.80 (3H,d,J12-CH₃,13 1Hz, 12-CH₃), 2.02 (3H,s ,4''-OCOCH₃), 2.06 (3H,s,2 '-OCOCH₃), 2.13 (3H,s,4'''-OCOCH₃), 2.35 (6H,s,3''-N(CH₃)₂), 3.19 (3H,s,3'-OCH₃), 3.46 (3H,s,2'''-OCH₃), 3.52 (3H,s,3'''-OCH₃), 4.30 (1H,d,J₁, ,_ax,2,,_ax 8Hz, H_{1 ' ' ax} ) , 4.62 (3H,d, J_{1' ' 'ax,2' ' 'ax} 8Hz, H_{1'' 'ax}), 4.65 (1H,d,J 16Hz, 4'-OCOCH₂OC₆H₅), 4.71 (1H,d,J 16Hz, 4'-OCOCH₂OC₆H₅), 4.89 (1H,m,H₁₅), 5.02 (1H,dd,J₁,eq^2,"

1Hz' J_1'eqr2'ax 4Hz, H_1'eq), 5.86 (1H'dq,J12-CH₃,13 1Hz, ^J13,14 10Hz, H₁₃), 6.25 (1H,d,J₁₀,₁₁ 16Hz, H₁₀), 6.90 (2H,d,J 9Hz, 4^,-OCOCH₂OC₆H₅ ( H₂ and H₆)), 6.98 (1H,dd,J 9Hz, J 9Hz 4'-OCOCH₂OC₆H₅ (H₄)), 7.29 (2H,dd,J 9Hz, J 9Hz, 4'-OCOCH₂OC₆H₅ (H₃ and H₅)), 7.30 (3H,d,J_10,11 16Hz, H₁₁), and 9.67 (1H,S,H₂₀). The more polar fractions afforded some unreacted 2',4',4''-tri-O -acetyldesmycosin (190 mg., 8%).

EXAMPLE 6

O-α-L-Cladinosyl-(1→3)-desmycosin

(a) 2',4',4''-Tri-O-acetyldesmycosin (Example 4(a)) (800 mg.) and 4-O-acetyl-1-deoxy-1-(pyridyl-2-thio)-α- and β- L-cladinoside (Example 1(d)) (1.53 g) were dissolved in dry acetonitrile (32 mL) under dry argon. A solution of anhydrous silver perchlorate (1.2 g.) in dry acetonitrile (33.1 mL) was added and the mixture was stirred under dry argon at 25°C for 21 h. The mixture was evaporated to dryness and the residue was taken up in dichlormethane and washed with water, the pH being adjusted to 10. The organic layer was dried (MgSO₄), filtered and evaporated to dryness. The residue was chromatographed on a silica gel column (15x5 cm.) using 20% acetone in hexane (v/v) as the eluant to give 2'',4'',4'''-tri-O-acetyl-O-(4'-O- acetyl-α-L-cladinosyl)-(1→3)-desmycosin (602 mg). The latter was dissolved in methanol (14.6 mL) containing 1,8-diazabicyclo [5.4.0] undec-7-ene (0.2768 mL) and the mixture was stirred under dry argon at 25°C for 44 h. The mixture was evaporated to dryness and the residue was chromatographed on a silica gel column (30x2 cm) using 3% methanol in chloroform (v/v) as the eluant to give O-α-L- cladinosyl-(1→3)-desmycosin ( 272 mg., 33%) contaminated with about 5-10% of O-α-L-cladinosyl-(1→3)-desmycosin seco acid methyl ester, which cochromatographed with the desired product.

(b) 2'',4'',4'''-Tri-O-acetyl-O-(4-O-phenoxyacetyl-α-L- cladinosyl)-(1→3)-desmycosin (Example 5(d)) (1.58 g.) was dissolved in methanol (186 mL) containing triethylamine (3.72 mL) (2% w/v solution) and the mixture was allowed to remain under dry argon at 25°C for 70 h. The solution was evaporated to dryness and the residue was chromatographed on a silrca gel column (60x2.5 cm.) using 4% methanol in chloroform (v/v) as the eluant to give O- α-L-cladinosyl-(1→3)-desmycosin (1.13g., 91%) as a colorless amorphous solid (Anal.: found: C, 59.15; H, 8.22; N, 1.44. C₄₇H_7gNO₁₇ 0.2 CHCl₃. requires: C, 59.17; H, 8.35; N, 1.47%); MS: m/z 930 (MH⁺); Rotation: [α]_D ²⁶ -43.8° (CHCl₃); UV: λ_maχ (CH₃OH) 283 nm (ε20,395); IR: vmax (CDCl₃) 3592, 3550, 1737, 1729, 1674, 1590, 1160

1057 cm^-1; ¹H-NMR: δg (CDCl₃) 0.89 (3H,t,J16 17-CH₃ 7Hz, 17-CH₃), 1.02 (3H,d,J 7Hz, CH₃ ) , 1.16 ( 3H, s , 3 ' -CH₃), 1.20 (3H,d,J 7Hz, CH₃), 1.21 (3H,d,J 7Hz, CH₃), 1.26 (3H,d,J 7Hz, CH₃), 1.27 (3H,d,J 7Hz, CH₃ ) , 1.79 (3H,d,J12-CH₃,13 1Hz, 12-CH₃), 2.52 (6H,s,3''-N(CH₃)₂) , 3.12 3H,s,3'-OCH₃), 3.46 (3H,s,2' ' '-OCH₃), 3.60 (3H,s,3' ' '-OCH₃), 4.29

(1H'd'J_{1 ' 'ax,2" ax} 8Hz, H_{1' 'ax}) , 4.54 (1H,d, J_{1' ' 'ax,2" ' 'ax} 8Hz, H_{1' ' 'ax}), 4.88 (1H'm,H₁₅), 4.92 (1H,dd,J_1'eq,2'eq 1Hz, J_{1'eq,2' ax} 4Hz, H_1'eq), 5.87 (1H,dq,J12-CH₃,13 1Hz, J_13,14 10Hz, H₁₃), 6.23 (1H,d,J_{10 ,1 1} 16Hz, H₁₀), 7.32 (1H,d,J_10,11 16Hz, E_{1 1} ) , and 9.71 (1H,s,H₂₀).

EXAMPLE 7

2",4",4'"-Tri-O-acetyl-20-deoxo-20-dihydro-O-(4'-O-phenoxyacetyl-α-L-cladinosyl)-(1→3)-desmycos in

(a) 2',4'-Di-Q-acetyl-20-deoxo-20-dihydrodesmycosin

20-Deoxo-20-dihydrodesmycosin prepared by reduction of desmycosin tosyl hydrazone with bis( triphenylphosphine) copper (I) tetrahydroborate as described in A.K. Ganguly et al., J. Chem. Soc., Chem. Commun., 1983, 1166 (3g.) and pyridine (3.2 mL were dissolved in dry dichloromethane (430 mL) and acetic anhydride (1.86 mL) was added. The mixture was stirred under dry argon at 25°C for 42 h. The solution was diluted with dichloromethane and washed with water, the pH being adjusted to 10. The organic layer was dried (MgSO₄), filtered and evaporated to dryness. The residue was chromatographed on a silica gel column (30×2 cm.) using 10% acetone in chloroform (v/v) as the eluant to give 2',4'-di-O-acetyl-20-deoxo-20-dihydrodesmycosin (2.92 g., 88%) as a colorless amorphous solid (Anal.: found: C, 60.77; H, 8.26; N, 1.27%; C₄₃H₇₁NO₁₅. 0.1 CHCl₃ requires: C, 60.47; H, 8.38; N, 1.64%); MS: m/z 842 (MH⁺); Rotation: [α]_D ²⁶ -8.2° (CHCl₃); UV: λ_max CF₃CH₂OH) 283 nm (ε22,537); IR: v_maχ (CDCl₃) 3560, 1744, 1720, 1678, 1596, 1235, 1168, 1057 cm^-1; ¹H-NMR: δ_H (CDCl₃) 0.82 (3H,t,J19,20-CH₃ 7Hz, 20-CH₃), 0 . 93 (3H,t,J16,17-CH₃ 7Hz, 17-CH₃), 0.95 (3H,d,J 7Hz, CH₃), 1.13 (3H,d,J 7Hz, CH₃), 1.18 (3H,d,J 7H:z , CH₃), 1.26 (3H,d,J 7Hz, CH3), 1.78 (3H,d,J12-CH₃,13 1Hz, 12-CH₃), 2.05 (3H,s,4'-OCOCH₃), 2.06 ( 3H,s,2'-OCOCH₃), 2.34 (6H,s,3'-N(CH₃)₂), 3.48 (3H,s,2''-OCH₃), 3.61 (3H,s,3"- OCH₃), 4.36 (1H.d,J_1'ax,2,ax 8Hz, H_1'ax), 4.55 (1H,d,J_{1' 'ax,2' 'ax} 8Hz, H_{1' 'ax}), 5.86 (1H,dq, J12-CH₃ , 13 1Hz, J_13,14 10Hz, H₁₃), 6.28 (1H,d,J_10,11 16Hz, H₁₀), and 7.29 (1H,d,J_10,11 16Hz, H₁₁).

(b) 2' ,4'-4''-Tri-O-acetyl-20-deoxo-20-dihydrodesmycosin 2',4'-Di O-acetyl-20-deoxo-20-dihydrodesmycosin (2.92 g), 4-N,N-dimethylaminopyridine (87 mg) and triethylamine (5 mL) were dissolved in dry dichloromethane (350 mL) and acetic anhydride (0.336 mL) was added. The mixture was stirred under argon at 25°C for 20 h. The reaction mixture was diluted with dichloromethane and washed with water, the pH being adjusted to 10. The organic layer was dried (MgSO₄), filtered and evaporated to dryness. The residue was chromatographed on a silica gel column (30x2 cm.) using 7% acetone in chloroform (v/v) as the eluant to give 21,4',4''-tri-O-acetyl-20-deoxo-20-dihydrodesmycosin (2.42 g., 79%) as a colourless amorphous solid (Anal: found: C, 60.33; H, 8.09; N, 1.57%; C₄₅H₇₃NO₁₆. 0.1 CHCl₃ requires: C, 60.32; H, 8.21; N, 1.56%); MS: m/z 884 (MH⁺); Rotation: [α]_D ²⁶ +11.2° (CHCl₃); UV: λ_max (CF₃CH₂OH) 283 nm (ε21,718), IR: v_max (CDCl₃) 3540, 1742, 1676, 1593, 1238, 1168, 1050 cm"1; 1H-NMR: δ_H (CDCl₃) 0.83 (3H,t,J19 20-CH₃ 7Hz, 20-CH₃), 0.92 (3H,t,J16,17-CH₃ 7Hz, 17-CH₃), 0.96 (3H,d,J 7Hz, CH3), 1.13 (3H,d,J 7Hz, CH3), 1.17 (3H,d,J 7Hz, CH₃), 1.19 (3H,d,J 7Hz, CH3 ) , 1.79 (3H,d,J12-CH₃ 13 1Hz, 12-CH₃), 2.06 (3H,s,4'-OCOCH₃), 2.07 (3H,s,2'-OCOCH₃), 2.13 ( 3H ,s,4''-OCOCH₃), 2.36 (6H,s,3'-N(CH3)2), 3.49 (3H,s,2''-OCH₃), 3.54 (3H,s,3"-OCH₃), 4.38 (1H,d,J_{1 'ax,2,ax} 8Hz, H_{1 'ax}), 4.63 (1H'd'J_{1"ax,2' 'ax} 8Hz, H_1"ax), 5.88 (1H,dq,J12.CH₃ ,13 1Hz, J13/14 10Hz, H13), 6.29 (1H,d,J_{10 ,11} 16Hz, H₁₀), and 7.32 (1H,d,J_10,11 16Hz, H₁₁).

(c) 2'',4'',4'''-Tri-O-acetyl-(4'-O-acetyl-α-L-cladinosyl)-(1→3)-20-deoxo-20-dihydrodesmycosin

2',4',4''-Tri-O-acetyl-20-deoxo-20-dihydrodesmycosin (800 mg) and 4-O-acetyl-1-deoxy-1-(pyridyl-2-thio)-α- and -β-L-cladinoside (Example 1(d) (1.55 g.) were dissolved in dry acetonitrile (34 mL) under dry argon. A solution of anhydrous silver perchlorate (1.22 g.) in dry acetonitrile (34 mL) was added and the mixture was stirred under dry argon at 25°C for 19 h. The mixture was evaporated to dryness and the residue was taken up in dichloromethane and washed with water, the pH being adjusted to 10. The organic layer was dried (MgSO₄), filtered and evaporated to dryness. The residue was chromatographed on a silica gel column (60×2 cm.) using 15% acetone in hexane (u/v) as the eluant to give 2'',4'',4' '-tri-O-acetyl-(4'-O-acetyl-α-L-cladinosyl)-(1→3)-20-deoxo-20-dihydrodesmycosin (396 mg., 40%) as a colorless amorphous solid; MS: m/z 1082 (MH⁺).

(d) 2",4",4"'-Tri-O-acetyl-20-deoxo-20-dihydro-O-(4'-O-phenoxyacetyl- α-L-cladinosyl)-(1→3)-20-deoxo-desmycosin

2",4',4'r-Tri-O-acetyl-20-deoxo-20-dihydrodesmycosin (1.83 g.) and 1-deoxy-4-O-phenoxyacetyl-1-(pyridyl-2-thio)-α- and -β-L-cladinoside (4.59 g.) were dissolved in dry acetonitrile (15 mL) under dry argon. A solution of anhydrous silver trifluoromethanesulphonate (3.46g) in dry acetonitrile (60.1 mL) was added and the mixture was stirred under dry argon at 25°C for 21 h. The mixture was evaporated to dryness and the residue was extracted with ethyl acetate and filtered. The ethyl acetate extract was evaporated to dryness and the residue was taken up in dichloromethane and washed with water the pH being adjusted to 10. The organic layer was dried (MgSO₄), filtered and evaporated to dryness. The residue was chromatographed on a silica gel column (60x2.5 cm.) using 5% increasing to 20% ethyl acetate in dichloromethane (v/v) as the eluant. Overlap fractions were rechromatographed on a silica gel column (30x2.5 cm.) using 15% ethyl acetate in dichloromethane (v/v) as the eluant to give 2'',4'',4 ''-tri-O-acetyl-20-deoxo-20-dihydro-O-(4'-O-phenoxyacetyl-α-L-cladinosyl)-(1→3)- desmycosin (1.26 g., 52%) as a colourless amorphous solid (Anal.: found: C, 62.43; H, 7.89; N, 1.24%; C₆₁H₉₃NO₂₁ requires: C, 62.28; H, 7.97; N, 1.19%); MS: m/z 1176 (MH⁺); Rotation: [α]_D ²⁶ -33.6° (CHCl₃); UV: λ_max (CF₃CH₂OH) 210 nm (ε10,676), 282 nm (ε23,146); IR: v_max (CDCl₃) 1740, 1673, 1591, 1235, 1164, 1050, 1016 cm^-1;¹H-NMR: δ_H (CDCl₃) 0.87 (3H,t,J19,20-CH₃ 7Hz, 20-CH₃), 0.89 (3H,t,J16 17-CH₃ 7Hz, 17-CH₃), 0.94 (3H,d,J 7Hz, CH₃), 1.05 (3H,s,3'-CH₃), 1.12 (6H,d,J 7Hz, CH₃), 1.16 (3H,d,J 7Hz, CH₃), 1.17 (3H,d,J 7Hz, CH₃), 1.78 (3H,d,J₁₂__{CH 13} 1Hz, 12-CH₃), 2.00 ( 3H,s,4''-OCOCH₃), 2.04 (3H,s,2"-OCOCH₃), 2.10 ( 3H,s,4'''-OCOCH₃), 2.34 (6H,s,3' -N(CH₃)₂), 3.18 ( 3H,s, 3'-OCH₃), 3.44 (3H,s,2'''-OCH₃), 3.50 (3H,s,3'''-OCH₃), 4.42 (1H,dd,J₄'''ax,5'''ax 10Hz, J_{3'' 'ax,4' ' 'ax} 2.5Hz, H₄,,,_ax), 4.46

(1H'd'J_1"ax,2"ax 8Hz, H_1''ax), 4.60

(1H'd'J_{1 , "ax,2' ' ' ax} 8Hz, H_{1 " ' ax}), 4.64 (1H'd'J 16Hz, 4'-OCOCH₂OC₆H₅), 4.70 (1H,d,J 16Hz, 4'-OCOCH₂OC₆H₅), 4.73

(H'dd'J_{3 " ax},_{4 " ax}=J_{4 " ax,5" ax}=10Hz, H_{4" ax}) , 4.76 (1H,d,J_{4 , ax,5, ax} 10HZ, H_{4 ,ax}) , 4.84 (1H,dd,J_{1 'eq,2 ' eq}

1Hz, J_1'eq,2'ax 4Hz, H_1'eq)' 4.86 (1H'-m,H₁₅), 4'88 (1H,dd,J_{1' 'ax,2' 'ax} 8Hz, J_{2' 'ax,3' 'ax} 10Hz, H_2"ax), 5.81 (1H,dq,J12-C_H3 13 1Hz, J_13,14 10Hz, H₁₃), 6.22 (1H,d,J_{10 ,11} 16Hz, H₁₀), 6.89 (2H,d,J 9Hz, 4'-OCOCH₂OC₆H₅ (H₂ and H₆)), 6.97 (1H,dd,J 9Hz, J 9Hz, 4'-OCOCH₂OC₆H₅ (H₄)), 7.24 (2H,dd,J 9Hz, J 9Hz, 4'-OCOCH₂OC₆H₅ (H₃ and H_e)), and 7.27 (1H,d,J_10,11 16Hz, H₁₁). The more polar fractions afforded unreacted 2 ',4',4''-tri-O-acetyl-20-deoxo-20-dihydrodesmycosin (490 mg., 27%).

EXAMPLE 8

O-α-L-Cladinosyl-(1→3)-20-deoxo-20-dihdyrodesmycosin

(i) 2'',4'',4'''-Tri-O-acetyl-(4,-O-acetyl-α-L- cladinosyl)-(1→3)-20-deoxo-20-dihydrodesmycosin (Example 7(c)) (456 mg.) was dissolved in methanol (11.1 mL) containing 1,8-diazabicyclo [5.4.0] undec-7-ene(0.21 mL) (1.93% w/v solution) and the mixture was stirred under argon at 25 °C for 45 h. The mixture was evaporated to dryness and the residue was chromatographed first on a silica gel column (30x2 cm.) using 3.3% methanol in chloroform (v/v) as the eluant, and then on a silica gel column (30x2 cm.) using 4% methanol in chloroform (v/v) as the eluant to give O-α-L-cladinosyl-(1→3)-20-deoxo-20-dihydrodesmycosin (241 mg) which contained about 33% of O-α-L-cladinosyl-(1→3)-20-deoxo-20-dihdyrodesmycosin seco acid methyl ester; MS: m/z 948 (MH⁺)- which could not be separated in any of the chromatographic systems tried. Additional signals arising from the seco acid methyl ester were also evident in the ¹H-NMR: δ_H (CDCl₃) 1.88 (3Hrs,J12-CH₃ , 13 1Hz, 12-CH₃), 3.23 (3H,s,3'-OCH₃), 3.55 (3H,s,1-COOCH₃), 4.26 (1H,d, J_{1' 'ax,2' 'ax} 8Hz, H_{1' 'ax}), 4.57 (1H,d,J_{1' ' 'aXr2' ' 'ax} 8Hz, H1IUaχ), 5.97 (lH,dq,

J12-CH₃,13 1Hz' J_13,14 10Hz, H13)' 6'23 (1H'd'J_10,11 16Hz, H₁₀), and 7.64 (1H,d,J_10,11 16Hz, H₁₁).

(ii) 2",4",4"'-Tri-O-acetyl-20-deoxo-20-dihydro-O- (4'-O-phenoxyacetyl-α-L-cladinosyl)-(1-→3)- desmycosin (Example 7(d)) (683 mg) was dissolved in methanol (81.7 mL) containing triethylamine (1.633 mL)(2% w/v solution) and the mixture was stirred at 25°C for 94 h. The solution was evaporated to dryness and the residue was chromatographed on a silica gel column (30x2.5 cm) using 4% methanol in chloroform (v/v) as the eluant to give O- α-L-cladinosyl-(1→3)-20-deoxo-20-dihydrodesmycosin (458 mg., 86%) as a colorless amorphous solid (Found: C, 61.11; H, 8.66; N, 1.43%; C₄₇H₈₁NO₁₆ requires: C, 61.62; H, 8.91; N, 1.53%); MS: m/z 916 (MH⁺); Rotation: [α]_D ²⁶ -45.0° (CHCl₃); UV: λ_max (CH₃OH) 282 nm (εl9,398), IR: v_max (CDCl₃) 3590, 3533, 1736, 1673, 1591, 1160, 1074, 1058 cm^-1; ¹H-NMR: δ_H (CDCl₃): 0.89 (3H, t, J19,20-CH₃ 7Hz, 20-CH₃), 0.91 ( 3H,t,J16,17-CH₃ 7Hz, 17-CH₃), 1.02 (3H,d,J 7Ηz, CH₃), 1.17 (3H,s,3'-CH₃), 1.19 (3H,d,J 7Hz, CH₃), 1.25 (3H,d,J 7Hz, CH₃), 1.26 (3H,d,J 7Hz, CH₃), 1.27 (3H,d,J 7Hz, CH₃ ) , 1.79 (3H,d,J12-CH₃ 13 1Hz, 12-CH₃), 2.55 (6H,s,3''-N(CH₃)₂), 3.16 (3H,s, 3'-OCH₃) , 3.46 (3H,s,2'''-OCH₃), 3.60 (3H,s,3'''-OCH₃), 4.32

(1H'd'J_1"ax,2"ax 8Hz, H_1"ax), 4'54 (1H'd,J_{1" ,ax,2'' 'ax} 8Hz, -H_{1' ' 'ax}), 4.77 (1H,dd,J_1'eq,2,eq 1Hz, J_1'eq,2'ax 4Hz, H_1'eq), 4.88 (1H,m,H₁₅), 5.84 (1H,dq,J12-CH₃,13 H₁₃), 6.21 (1H,d,J_10,11 16Hz, H₁₀), and 7.27 (1H,d,J_10,11 16Hz, H₁₁).

EXAMPLE 9

O-α-L-Cladinosyi-(1→3)-19-deformyldesmycosin (a) 19-Deformyldesmycosin

Desmycosin (Merck Index, Tenth Edition p. 1405) (18.9 g) was dissolved in degassed benzene (580 mL) and tris (triphenylphosphine)rhodium chloride (29.5 g.) was added. The mixture was heated under dry nitrogen at 90°C for 16 h. The mixture was diluted with ethyl acetate and extracted twice with 0.2N hydrochloric acid. The aqueous acid layer was adjusted to pH 10 and extracted with dichloromethane. The latter was dried (MgSO₄), filtered and evaporated to dryness. The residue was chromatographed on a silica gel column (60×5 cm.) using 5% methanol in chloroform (v/v) as the eluant to give 19-deformyldesmycosin (13.2 g., 73%) as a colorless amorphous solid (Anal.: found: C, 57.05; H, 7.99; N, 1.62%. C₃₈H₆₅NO₁₃. 0.5 CHCl₃ requires: C, 56.79; H, 8.15; N, 1.74%); MS: m/z 744 (MH⁺); Rotation: [α]_D ²⁶ 0° (CHCl₃); UV: λ_max (CH₃OH) 282 nm (ε20,676); IR: v_max (CDCl₃) 3540, 3450, 1705, 1670, 1590, 1185, 1163, 1055 cm^-1; ¹H-NMR: δ_H (CDCl₃) 0.92 (3H,t,J16 17-CH₃ 7Hz, 17-CH₃), 1.02 (3H,d,J 7Hz, CH₃), 1.03 (3H,d,J 7Hz, CH₃), 1.18 (3H,d,J 7Hz, CH₃), 1.26 (3H,d,J 7Hz , CH₃). 1.30 (3H,d,J 7Hz, CH₃), 1.78 (3H,d,J12-CH₃,13 1Hz, 12-CH₃), 2.53 (6H,s,3'-N(CH₃)₂), 3.48 (3H,s,2''-OCH₃), 3.60 (3H,s,3''-OCH₃), 4.28 (1H,d,J_1'ax,2'ax 8Hz, H_1'ax), 4.55 (1H,d,J_{1' 'ax,2' 'ax} 8Hz, H_{1' 'ax}), 4.97 (1H,m,H₁₅), 5.82 (1H,dq,J12-CH₃ 13 1Hz, J_13,14 10Hz, H₁₃), 6.24 (1H,d,J_10,11 16Hz, H₁₀), and 7.24 (1H,d,J_{10 ,11} 16Hz, H₁₁).

(b) 2',4'-Di-O-acety1-19-deformyldesmycosin

19-Deformyldesmycosin (12 g) was dissolved in dry acetone (100 mL) and acetic anhydride (7.6 mL) was added. The mixture was allowed to remain at 25 °C for 17 h. The solution was evaporated to dryness and the residue was azeotroped with toluene to give 2',4'-di-O-acetyl-19-deformyldesmycosin (11.5 g., 86%) as a colorless amorphous solid that was used without further purification.

An aliquot (800 mg) was chromatographed on a silica gel column (15×2.5 cm.) using 10% acetone in hexane as the eluant to give 2',4'-di-O-acetyl-19-deformyldesmycosin (680 mg) (Anal.: found: C, 60.86, H, 8.49; N, 1.87%. C₄₂H₆₉NO₁₅ requires: C, 60.92; H, 8.40; N, 1.69%); MS: m/z 828 (MH⁺); Rotation: [α]_D ²⁶ +11.9° (CHCl₃); UV: λ_max (CF₃CH₂OH) 283 nm (ε23,838); IR: v_max (CDCl₃) 3543, 1742, 1712, 1675, 1590, 1233, 1184, 1174, 1055 cm^-1; 1H-NMR: δ_H (CDCl₃) 0.92 ( 3H, t,J16 17-CH₃ 7Hz, 17-CH₃), 0.93 (3H,d,J 7Hz, CH₃), 1.03 (3H,d,J 7Hz, CH₃), 1.14 (3H,d,J 7Hz, CH₃), 1.18 (3H,d,J 7Hz, CH₃), 1.25 (3H,d,J 7Hz, CH3), 1.77 (3H,d,J12-CH₃,13 1Hz, 12-CH₃), 2.05 (6H,s,2'and 4'-OCOCH₃), 2.34 ( 6H,s,3'-N(CH₃)₂), 3.46 (3H,s,2''-OCH₃), 3.60 (3H,s,3"-OCH₃), 4.33 (1H'd'J_1'ax,2'ax 8Hz, H_1'ax)' 4.54 (1H'd'J1"ax,2"ax 8Hz, H_{1' 'ax}), 4.74 (1H,dd,J_3,ax,4,ax= J_4'ax,5'aχ=10Hz,

H_4,ax), 4.90 (1H,dd,J_1'ax,2,ax 8Hz, J2'aXf3'ax 10Hz, H_2'ax), 4.92 (1H,m,H₁₅), 5.83 (1H,d,J_10,11 16Hz, H₁₀), and 7.27 (1H,d,J_10,11 16Hz, E_{1 1} ) .

(c) 2',4',4''-Tri-O-acetyl-19-deformyIdesmycosin

2',4'-Di-O-acetyl-19-deformyldesmycosin (10.3 g.), 4-dimethylaminopyridine (304 mg) and triethylamine ( 17 . 3 mL ) were dissolved in dry dichloromethane ( 300 mL ) and acetic anhydride (1.174 mL) was added. The mixture was allowed to remain at 25°C for 22 h. under dry argon. The mixture was extracted with water at pH 8.5. and .the dichloromethane layer was dried (MgSO₄), filtered and evaporated to dryness. The residue was chromatographed on a silica gel column (60x5 cm.) using 10% increasing to 15% acetone in hexane (v/v) as the eluant to give 21,4',4''-tri-O-acetyl-19-deformyldesmycosin (8.1 g., 75%) as a colorless amorphous solid (Anal.: found: C, 60.88; H, 8.42; N, 1.31%; C₄₄H₇₁NO₁₆ requires: C, 60.74; H, 8.23; N, 1.61%); MS: m/z 870 (MH⁺); Rotation: [α]_D ²⁶ +25.3° (CHCl₃); UV: λ_max (CF₃CH₂OH) 284 nm (ε22,479); IR: v_max (CDCl₃) 3520, 1737, 1672, 1590, 1234, 1181, 1161, 1050 cm"1; 1H-NMR: δ_H (CDCl₃) 0.90 (3H,t,J16/17-CH₃ 7Hz, 17-CH₃), 0.94 (3H,d,J 7Hz, CH₃), 1.03 (3H,d,J 7Hz, CH₃), 1.13 (3H,d,J 7Hz, CH3), 1.16 (3H,d,J 7Hz, CH₃), 1.18 (3H,d,J 7Hz, CH₃), 1.77 (3H,d,J12-CH_3,13 1Hz, 12-CH₃), 2.05 (6H,s,2' and 4''-OCOCH₃), 2.10 (3H,s,4''-OCOCH₃), 2.33 (6H,s,3'-N(CH₃)₂), 3.46 (3H,s,2''-OCH₃), 3.51 (3H,s,3''-OCH₃), 4.33 (1H,d,J_1'ax,2,ax 8Hz, H_1'ax), 4.42

(1H,dd,J_{3''eq,4' 'ax} 3HZ, J_{4' 'ax,5' 'ax} 10HZ, H_{4' ,ax}), 4.60 (1H,d,J_{1' 'ax,2' 'ax} 8Hz, H_{1' 'ax}), 4.75

(1H'dd'J_3'ax,4'ax=J_4'ax,5-ax=10Hz, H_4'ax), 4.88 (1H,dd,J_1'ax2'ax 8HZ, J_2'ax,3'ax 10HZ, H_2'ax), 4.92

(1H,m,H₁₅), 5.82 (1H,dq,J12-CH₃ 13 1Hz, J_13,14 10Hz,

H₁₃), 6.28 (1H,d,J_{10, 11} 16Hz, H₁₀) and 7.26 (1H,d,J_{10 ,11}

16Hz, H₁₁). The more polar fractions afforded unreacted

2',4'-di-O-acetyl-19-deformyldesmycosin (1.35 g., 13%).

(d) 2'',4'',4'',-Tri-0-acetyl-19-deformyl-O-(4'-O-phenoxyacetyl-α-L-cladinosyl)-(1→3)-desmycosin

2',4',4''-Tri-O-acetyl-19-deformyldesmycosin (2.5 g) and 1-deoxy-4-O--phenoxyacetyl-1-(pyridyl-2-thio)-α- and -β-L-cladinoside (6.38 g.) were dissolved in dry acetonitrile (50 mL) under dry argon. A solution of anhydrous silver triflu romethanesulphonate (4.8 g.) dissolved in dry acetonitrile (50 mL) was added and the mixture was stirred under dry argon at 25 °C for 20 h. The mixture was evaporated to dryness and the residue was extracted with ethyl acetate and filtered. The ethyl acetate was removed in vacuo and the residue was taken up in dichloromethane and washed with water, the pH being adjusted to 10. The organic layer was dried (MgSO₄), filtered and evaporated to dryness. The residue was chromatographed on a silica gel column (30x2.5 cm) using 5% increasing to 20% ethyl acetate in dichloromethane (v/v) as the eluant. The product was rechromatographed on a silica gel column (30×2.5 cm.) using 20% ethyl acetate in dichloromethane as the eluant to give 2'',4'',4'''-tri-O-acetyl-19-deformyl-O-(4,-O- phenoxyacetyl-α-L-cladinosyl)-(1 →3)-desmycosin (2.04 g., 61%) as a colorless amorphous solid (Anal.: found: C, 62.00; H, 7.84; N, 1.22%; C₆₀H₉₁NO₂₁ requires: C, 62.00; H, 7.89; N, 1.21%); MS: m/z 1162 (MH⁺); Rotation: [α]_D ²⁶ -23.1° (CHCl₃); UV: λ_maχ (CF₃CH₂OH) 210 nm (ε7,561), 283nm (ε17,856); IR: v_maχ (CDCl₃) 1737, 1673, 1590, 1234, 1188, 1160, 1050, 1012 cm^-1; ¹H-NMR: δg (CDCl₃) 0.90 (3H,t,J₁6,17-CH₃ 7Hz, 17-CH₃), 0.92 (3H,d,J 7Hz, CH₃), 1.03 (3H,d,J 7Hz, CH₃), 1.05 (3H,s,3'-CH₃), 1.11 (3H,d,J 7Hz, CH₃), 1.14 (3H,d,J 7Hz, CH₃), 1.17 (3H,d,J 7Hz, CH₃), 1.18 (3H,d,J 7Hz, CH₃), 1.76 (3H,d,J12-CH₃,13 1Hz, 12-CH₃), 2.02 (3H,s, 4''-OCOCH₃), 2.04 (3H,s,2''-OCOCH₃), 2.12 (3H,s,4'''-OCOCH₃), 2.35 (6H,s,3''-N(CH₃)₂), 3 . 21 (3H,S,3'-OCH₃), 3.44 (3H,s,2'''-OCH₃), 3.51 (3H,s,3'''-OCH₃), 4.37 (1H,d,J_{1' 'ax,2' 'ax} 8Hz, H_{1' 'ax}), 4.41 (1H,dd,J₃'''eq,4'''ax 2.5Hz, J4'''ax,5'''ax 10Hz, H_{4' ' 'ax}), 4.60 (1H,d,J_{1' ' 'aX,2' ' 'ax} 8Hz, H_{1' ' 'ax}), 4.66 (1H,d,J 16Hz, 4'-OCOCH₂OC₆H₅), 4.71 (1H,d,J 16Hz, 4'-OCOCH₂OC₆H₅), 4.75 (1H,dd,J_{3' 'ax,4' 'ax}=J_{4' 'ax,5' 'ax}=10Hz, H_{4' 'ax}), 4.76 (1H,d,J_4'ax,5'ax 10HZ, H₄,_ax), 4.87 (1H,m,H₁₅), 4.90 (1H,dd,J_{1' 'ax,2' 'ax} 8Hz, J_{2' 'ax,3' 'ax} 10HZ, H_{3' 'ax}), 4.97 (1H,dd,J_1'eq,2'eq 1Hz, J_{1'eq, 2-ax} 4Hz, H_1'eq), 5.80 (1H,dq,J12-CH₃,13 1Hz, J_13,l4 10Hz, H₁₃), 6.24 (1H,d,J_{10, 1 1} 16Hz, H₁₀), 6.90 (2H,d,J 9Hz, 4'-OCOCH₂OC₆H₅ (H₂ and H₆)), 6.97 (1H,dd,J 9Hz, J 9Hz, 4'-OCOCH₂OC₆H₅ (H₄)), 7.27 (2H,dd,J 9Hz, J 9Hz 4'-OCOCH₂OC₆H₅ (H₃ and H₅)), and 7.28 (1H,d,J_{10, 1 1} 16Hz, H₁₁). The more polar fractions afforded unreacted 2',4',4''-tri-O-acetyl-19-deformyldesmycosin (450 mg., 18%). (e) O-α-L-Cladinosyl-(1→3)-19-deformyldesmycosin

2'',4'',4'''-Tri-O-acetyl-19-deformyl-O-(4'-O-phenoxyacetyl-α-L-cladinosyl)-(1→3)-desmycosin (1.9g) was dissolved in methanol (165 mL) containing triethylamine (4.546 mL) (2% w/v solution) and the mixture was allowed to remain at 25°C for 72 h. The solution was evaporated to dryness and the residue was taken up in dichloromethane and washed with water, the pH being adjusted to 10. The organic layer was dried (MgSO₄), filtered and evaporated to dryness. The residue was chromatographed on a silica gel column (60×2.5 cm.) using 4% methanol in chloroform (v/v) as the eluant. The resulting product was rechromatographed on a silica gel column (15x2.5 cm.) using ethyl acetate as the eluant to afford O -α-L-cladinosyl-(1→3)-19-deformyldesmycosin (1.28g., 87%) as a colourless amorphous solid (Anal.: found: C, 61.40; H, 8.99; N, 1.45%; C₄₆H_y9NO₁₆ requires: C, 61.24; H, 8.83; N, 1.55%); MS: m/z 902 (MH+); Rotation: [α]_D ²⁶ -35.6° (CHCl₃); UV: v_max (CH₃OH) 382 nm (ε20,942); IR: v_maχ (CDCl₃) 3600, 3558, 3450, 1738, 1732, 1674, 1592, 1160, 1058, 1010 cm^-1; ¹H-NMR: δ_H (CDCl₃) 0.92 (3H,t,J16,17-CH₃ 7Hz, 17-CH₃), 1.02 (3H,d,J 7Hz, CH₃), 1.07 (3H,d,J 7Hz, CH₃), 1.17 (3H,s,3'-CH₃), 1.19 (3H,d,J 7Hz, CH₃), 1.26 (3H,d,J 7Hz, CH₃), 1.27 (3H,d,J 7Hz, CH₃), 1_*29 (3H,d,J 7Hz, CH₃), 1.77 (3H,d,J12-CH₃,13 1Hz, 12-CH₃), 2.50 (6H,s,3''-N(CH₃)₂), 3.17 (3H,s,3'-OCH₃), 3.45 (3H,s,2'''-OCH₃), 3.60 (3H,s,3'''-OCH₃), 4.24 (1H,d, J_1''ax,2''ax 8Hz, H_{1' 'ax}), 4.53 (1H,d,J_{1' ' 'ax/2' ''ax} 8Hz, H_{1' ' 'ax}), 4.86 (1H,m,H₁₅), 4.90 (1H,dd,J_1'eq/2'eq 1Hz, J_1'eq,2'ax 4Hz, H_1'eq), 5.82 (1H,dq,J12-CH₃,13 1Hz, J_13,14 10Hz, H₁₃), 6.23 (1H,d,J_10,11 16Hz, H₁₀), and 7.26 (1H,d,J_10,11 16Hz, H₁₁). EXAMPLE 10 α- and - β-O-Tetrahydropyranyl-(1→3)-rosaramicin

(a) (1R/S)-S-(Pyridyl-2-thio)-tetrahydropyran

Dihydropyran (dry, redistilled) (48 mL) and 2- mercaptopyridine (6.66g.) were dissolved in dry dichloramethane (70 mL) under dry nitrogen. Biorad AG50W-X8 (200-400 mesh) sulphonic acid cation exchange resin (H+ form) (23 g.) (dried by azeotroping with toluene) was added and the mixture was stirred in the dark at 25°C for 72 h. The resin was filtered off, washed with dichloromethane and the combined filtrates were evaporated to dryness. The residue was chromatographed on silica gel column (280 g.) using initially 50% hexane in dichloromethane, followed by 25% hexane in dichloromethane and finally 1% ethyl acetate in dichloromethane (all v/v) as the eluant to give a 30:70 mixture (w/w) of (1R/S)-N-(pyridyl-2-thione)- tetrahydropyran and (1R/S)-S-(pyridyl-2-thio)- tetrahydropyran (8.31g.) The more polar fractions afforded additional pure (1R/S)-S-(pyridyl-2-thio)-tetrahydropyran (2.4 g.) upon rechromatography as described above. In order to obtain analytically pure samples of each component of the mixture, a portion of the mixture (0.65 g.) was rechromatographed on an alumina column (100 mL capacity) using 4% increasing to 6%. and then 8% of ethyl acetate in hexane (all v/v) as the eluant to give in the order of elution (1R/S)-S-(pyridyl-2-thio)-tetrahydropyran (177 mg.) as a yellow oil; MS: m/z 196 (MH⁺); Rotation: [α]_D ²⁶ 0° (CH₃OH); UV: λ_max (CH₃OH) 242 nm (ε9,055) 285 nm (ε4,348); IR: v_max (CHCl₃), 1573, 1555, 1427, 1416, 1185, 1121, 1100, 1076,

1038, 1008 cm^-1 1H-NMR: δ_H (CDCl₃) 1.60-2.00, 2.12 (5 H and 1H, m, H₂, H₃, H₄), 3.71 (1H,ddd,J_5aχ,5eqf 12Hz, J₄eq,5ax 4Hz, J_4ax,5ax 10 . 5Hz , H_{5 a x}), 4.14 (1H,ddd,J_5ax,5eq 12Hz, J_4eq,5eq=J_4ax,5eq=6Hz, H_5eq), 5.99 (1H,dd,J_1eq,2eq 5Hz, J_1eq,2ax 5.5Hz, H_1eq), 7.06 (1H,ddd,J4 5 8Hz, J_5,6 5Hz, J_3,5 1.2Hz, 1-S-C₅H₄N(H₅)), 7.34 (1H,ddd,J_3,4 8Hz, J_3,5=J_3,6=1.2Hz, 1-S-C₅H₄N(H₃)), 7.54 (1H,ddd,J_3,4=J_4,5=8Hz, J_4,62Hz, 1-S-C₅H₄N(H₄)), and 8.51 (1H,ddd,J_5,6 5Hz, J_3,6 1.2Hz, J_4,6 2Hz, 1-S-C5H₄N(H₆)) , and (1R/S)-N-(pyridyl-2-thione)-tetrahydropyran (233 mg.) as a yellow oil; MS: m/z 196 (MH⁺); Rotation: [α]_D ²⁶ -0.6° (CH₃OH); UV: λ_max (CH₃OH) 283 nm (ε11,029), 360 nm (ε6,290); IR: v_max (CHCl₃) 1614, 1527, 1452, 1419, 1253, 1207, 1180, 1115, 1079, 1042 cm^-1; ¹H-NMR: δ_H (CDCl₃) 1.24, 1.60-2.08, 2.50 (1H, 4H and 1H, m, H₂, H₃, H₄), 3.80 (1H,ddd,J_5ax,4eq 4.5Hz,

J_5ax,4ax=J_5ax,5eq=11Hz, H_5ax], 4.24 (1H,ddd,J_5eq,5ax

11Hz' J_5eq,4eq=J_5eq,4ax=2Hz, H_5eq), 6.70 (1H,dd,J_1ax,2ax 10.5Hz, J_1ax,2eq 2.5Hz, H_1ax), 6.73

(1H,ddd,J_4,5=J_5,6=7Hz, J_3,5 1Hz, l-S-C₅H₄NS(H₅)), 7.19

(1H,ddd,J_3,4 9Hz, J_4,5 7Hz, J4,6 2Hz, 1-S-C₅H₄N(H₄)),

7.68 (1H,ddd,J_3,4 9Hz, J_3,5=J_3,6=1Hz, 1-S-C₅H₄N(H₃)) and

8.04 (1H,ddd,J_5,6 7Hz, J_4,6 2Hz, J_{3 , 6} 1Hz, 1-S- C₅H₄N(H₆)).

(b) α- and β-O-Tetrahydropyranyl-(1→3)-rosaramicin

2^,-O-Acetylrosaramicin (prepared by acetylation of rosaramicin using acetic anhydride in acetone by the method described in H. Reimamm, et al. J. Chem. Soc., Chem. Comm., 1972, 1270) (2g.), anhydrous silver trifluoromethanesulphonate (6 g.) and dry triethylamine (2.8 mL) were dissolved in dry acetonitrile (30 mL). (1R/S)-S-(pyridyl-2-thio)-tetrahydropyran (4 mL) was added and the mixture was stirred under dry nitrogen at 25°C for 24 h. The reaction mixture was evaporated to dryness and the residue was taken up in dichloromethane and washed with 5% aqueous sodium bicarbonate. The dichloromethane layer was filtered, washed with water, dried (Na₂SO₄), filtered and evaporated to dryness. The residue was triturated with ethyl acetate and filtered. The solids were washed with ethyl acetate and the combined filtrates were evaporated to dryness. The residue was chromatographed on a silica gel column (200 g.) using 10%, 20%, 25% and finally 45% acetone in toluene (v/v) as the eluant to give a ca. 8:5 mixture of the less polar and more polar diastereoisomers of 2'-O- acetyl-O-tetrahydropyranyl-(1→3)-rosaramicin (1.16 g., 51%). The early fractions that were rich in the less polar diastereoisomer (327 mg) were rechromatographed on a silica gel column (32 g.) using acetone: dichloromethane: toluene: (v/v/v) (20:60:44) as the eluant to give the less polar diastereoisomer (190 mg). The latter was taken up in methanol (1.5 mL) and allowed to remain at 25°C for 17 h. The mixture was evaporated to dryness to give O-tetrahydropyranyl-(1→3)-rosaramicin as a colourless amorphous solid (Found: C, 64.56; H, 8.78; N, 2.27. C₃₆H₅₉NO₁₀ requires: C, 64.94; H, 8.93; N, 2.10%; MS: m/z 666 (MH⁺); Rotation: [α]_D ²⁶ -42.5° (CHCl₃); UV: λ_max (CH₃OH) 240 nm (ε12,271); IR: v_max (CDCl₃) 3440, 1740, 1720, 1687, 1619, 1167, 1118, 1076, 1032, 986 cm^-1; ¹H-NMR: δ_H (CDCl₃) 0.89 (3H,t,J_16,17-CH₃ 7Hz, 17-CH₃), 1.11 (3H,d,J 7Hz, CH₃), 1.12 (3H,d,J 7Hz, CH₃), 1.13 (3H,d,J 7Hz, CH₃), 1.19 (3H,d,J 7Hz, CH₃), 1.37 (3H,s,12-CH₃), 2.27 (6H,s,3''-N(CH₃)₂), 4.14

(1H,d,J_{1' 'ax,2' 'ax} 8Hz, H_{1' 'ax}), 4'73 (1H,m,H₁₅), 4.76 (1H,dd,J_1'eq,2'eq 2Hz, J_1.eq,2,ax 7Hz, H_1Ieq), 6.36 (1H,d,J_{10 ,1 1} 16Hz, H₁₀), 6.52 (1H,d,J_10,11 16Hz, H₁₁), and 9.66 (1H,s,H₂₀). The later fractions from the original column that were rich in the more polar diastereoisomer (327 mg) were rechromatographed on a silica gel column (40g.) using first 10%, then 14% and finally 20% acetone in dichloromethane: toluene::60:44 (v/v) as the eluant to give the more polar diastereoisomer (40 mg.). The latter was taken up in methanol (0.5 mL) and allowed to remain at 25°C for 17 h. The solution was evaporated to dryness to give O-tetrahydropyranyl-(1→3)-rosaramicin as a colourless amorphous solid; MS: m/z 666 (MH⁺); Rotation: [α]_D ²⁶ -35.1° (CHCl₃); UV: λ_maχ (CH₃OH) 239 nm (εll,264); IR: v_max (CHCl₃) 3430, 1738, 1725, 1687, 1619, 1178, 1168, 1117, 1078/ 1032, 987 cm^-1; ¹H-NMR: δ_H (CDCl₃) 0.90 (3H,t,J16,17-CH₃ 7Hz, 17-CH₃), 1.12 (3H,d,J 7Hz, CH₃), 1.16 (3H,d,J 7Hz, CH₃), 1.18 (3H,d,J 7Hz, CH₃), 1.20 (3H,d,J 7Hz, CH₃), 1.43 (3H,s,12-CH₃), 2.29 (6H,s,3''-N(CH₃)₂), 4.30 (1H,d,J_1''ax,2"ax 7.5Hz, H_{1' 'ax}), 4.72 (1H,dd,J_1'eq,2'eq 2Hz, J_1'eq,2'ax 7.5Hz, H_1'eq), 4.84 (1H,m,H₁₅), 6.42 (1H,d,J_10,11 16Hz, H₁₀), 6.59 (1H,d,J_10,11 16Hz, H₁₁), and 9.77 (1H,s,H₂₀).

EXAMPLE 11 (starting materials)

3,4-Di-O-(para-methoxybenzyl)-1-deoxyl-(pyridyl-2-thio)- α- and -β-L-digitoxoside

Follow the procedure of Brimacombe et al., J. Chem. Soc, Perkin I, 1982, 2583, to prepare methyl 3-oxo-3-dehydro-L-digitoxoside which is treated with NaBH₄ in methanol to prepare methyl α-L-digitoxoside. React methyl α-L-digitόxoside with more than two equivalents of para-methoxybenzyl triflate in the presence of excess 2,4,6-trimethylpyridine to obtain methyl 3,4-di-O-(para-methoxybenzyl)-α-L-digitoxoside. Contact methyl 3,4,-di-O-para-methoxybenzyl)-α-L-digitoxoside with IN aqueous HCl at 25°C to produce 3,4-di-O-(para-methoxybenzyl)-α and β-L-digitoxose. React a solution of the 3,4,-di-O-(para-methoxybenzyl)α- and β-L-digitoxose in dichloromethane with a solution 2,2'-dipyridyldisulfide and tri-n-butyl phosphine in dichloromethane to produce the title compound.

EXAMPLE 12 (starting materials)

3-O-Acetyl-4-O-methyl-1-deoxy-1-(pyridyl-2-thio)-α- and β-L-digitoxoside

Treat methyl 3-oxo-3-dehydro-L-digitoxoside with methyltriflate in 2,4,6-trimethylpyridine to obtain methyl 4-O-para-methoxybenzyl-3-oxo-3-dehydro-L- digitoxoside. React methyl 4-O-para-methoxybenzyl-3-oxo- 3-dehydro-L-digitoxoside with sodium borohydride in methanol to obtain methyl 4-O -methyl-α-L-digitoxoside. Treat methyl 4-O-methyl-α-L-digitoxoside with 0.1N aqueous HCl to obtain 4-O-methyl-α- and β-L-digitoxose which is reacted sequentially with acetic anhydride in the presence of pyridine and thereafter with IN aqueous HCl and therafter with a solution of 2,2'-dipyridyldisulfide and tri-n-butylphosphine in dichlormethane to produce the title compound.

EXAMPLE 13 (starting materials)

3-O-Methyl-4-O-para-methoxybenzyl-1-deoxy-1-(pyridyl-2-thio)-α- and β-L-digitoxside

Treat methyl 3-oxo-3-dehydro-L-digitoxoside with para-methoxybenzyl triflate in the presence of 2,4,6-trimethylpyridine to produce methyl 4-O-para-methoxybenzyl-3-oxo-3-dehydro-L-digitoxoside which is thereafter reduced with sodium borohydride in methanol to give methyl 4-O-para-methoxybenzyl-α-L-digitoxoside. Contact methyl 4-O-para-methoxybenzyl-α-L-digitoxoside sequentially with silver (II) oxide and methyl iodide in dimethylformamide, then with 1N aqueous HCl and finally with 2,2'-dipyridyldisulfide in the presence of tri-n-butylphosphine to give the title compound. EXAMPLE 14 (starting materials)

3,4-Di-O-Methyl-1-deoxy-1-(pyridyl-2-thio)-α- and -β-L-digitoxoside

Treat methyl α-L-digitoxoside with two equivalents of methyl triflate in the presence of 2,6-ditert-butylpyridine to give methyl 3,4-di-O-methyl-α-L-digitoxoside which is thereafter sequentially treated with 1N aqueous HCl and then 2,2'-dipyridyldisulfide in the presence of tri-n-butylphosphine to give the title compound.

EXAMPLE 15

O-α-L-Cladinosyl-(1→3)-23-O-demycinosyl-4'''-O-iso-valeryltylosin

Treat 23,2'-di-O-acetyl-23-O-demycinosyl-4"-O- iso-valeryltylosin (prepared as described in International Publication No. WO 87/03880, published 2 July 1987) with 1-deoxy-4-0--phenoxyacetyl-1-(pyridyl-2-thio)-α- and -β-L-cladinoside (Example 5(c)) in the presence of anhydrous silver trifluoromethanesulphonate to afford 23 ,2"-di-O-acetyl-23-O-demycinosyl-4'''-O-iso-valeryl-O-(4'-O-phenoxyacetyl-α-L-cladinosyl)-(1→3)-tylosin. Treatment of the latter with 2% (v/v) triethylamine in methanol affords the title compound.

EXAMPLE 16

23,2"-Di-O-acetyl-O-α-L-cladinosyl-(1→3)-23-O-demycinosyl-4"-O-iso-valeryltylosin

Treat 23,2^,-di-2_-acetyl-23-O-demycinosyl-4''-O-iso-valeryltylosin (prepared as described in International Publication No. WO 87/03880, published 2 July 1987, especially the acylation Schemes I and II) with 1-deoxy-4-α-phenoxyacetyl-1-(pyridyl-2-thio)-α- and -β-L-cladinoside (Example 5(c)) in the presence of anhydrous silver trifluoromethanesulphonate to give 23 ,2"-di-O-acetyl-23-O-demycinosyl-4"-O-iso-valeryl-O- (4'-O-phenoxyacetyl-α-L-cladinosyl)-(1→3)-tylosin. Treatment of the latter with 2% (v/v) triethylamine in methanol, followed by subsequent treatment of product with acetic anhydride in acetone, gives the title compound.

EXAMPLE 17

O-(4'-O-Acetyl-α-L-cladinosyl)-(1→3)-23-O-demycinosyltylosin

Treat 23,2',4"-tri-O-phenoxyacetyl-23-O-demycinosyltylosin (prepared by the methods described in International Publication No. WO 87/03880, published 2 July 1987 especially the acylation Schemes I and III) with 1-deoxy-4-O-acetyl-1-(pyridyl-2-thio)-α- and -β-L-cladinoside (Example 1(d)) in the presence of anhydrous silver trifluoromethanesulphonate and subsequently with 2% (v/v) triethylamino in methanol to give the title compound.

In a similar fashion the corresponding 4'-O-propionyl, 4'-O-butyryl and O-(4'-O-iso-valeryl-α-L-cladinosyl)-(1→3)-23-O-demycinosyltylosins may be prepared by substitution of an equivalent quantity of propionic anhydride, butyric anhydride or iso-valeric anhydride for acetic anhyride in the preparation of the cladinose derivative described in Example 1 above. EXAMPLE 18

3-O-(2-Methoxy-1-butyloxymethyl)-12,13-dehydro-12,13-deoxorosaramicin

2-Methoxy-1-butanol (prepared by standard methods known in the art, for example those described in CA, 1984, Vol. 101, 6616f and CA, 1984, Vol. 100, 209159 m.) is reacted with formaldehyde and 90% HCl to give 2-methoxy-1-butyloxymethyl chloride. The latter reacts with 2'-O-acetyl-12,13-dehydro-12,13-deoxorosaramicin of Example 2(a) in the presence of a tertiary amino base, followed by reaction with a lower alkanol such as methanol, to give the title compound.

EXAMPLE 19

O-(1-Ethoxyethyl)-(1→3)-rosaramicin

(a) 2-S-(1-Ethoxyethyl)mercaptopyridine

2-Mercaptopyridine (0.666 g) was dissolved in dry dichloromethane (7 ml.) and the solution was cooled to 0°C. Ethyl vinyl ether (5 ml) (which had been distilled^ over sodium) and BioRad 50Wx4 sulphonic acid resin (H⁺ cycle) (2.3g) were added and the mixture was allowed to warm gradually to 25°C overnight. After 17h the resin was filtered off and washed with dry dichloromethane. The combined filtrates were evaporated to dryness and the residue was chromatographed on a silica gel column (50 g) using first hexane, then 50% hexane in dichloromethane (v/v), then 25% hexane in dichloromethane (v/v), then dichloromethane, then 1% ethyl acetate in dichloromethane (v/v) and finally 2% ethyl acetate in dichloromethane (v/v) to. give 2-S-(1-ethoxyethyl)-mercaptopyridine, MS: m/z 184 (MH⁺); ¹H- NMR: δ_H (CDCl₃) 1.21 (3H,t,J 7Hz, OCH₂CH₃) , 1.55

S (3H),d,J 7Hz, CH-CH₃), 3.50 (2H,m, 0CH₂CH₃), 6.78

O (1H,m -1-S-C₅H₄N), 7.20 (1H,m,1-S-C₅H₄N), 7.68 (1H,m,1-S- C₅H₄N) and 7.95 (1H,m, 1-S-C₅H₄N).

(b) O-(1-Ethoxyethyl)-(1→3)-rosaramicin

2'-O-Acetylrosaramicin (100 mg), 2-S-(1- ethoxyethyl)mercaptopyridine (0.18 ml), anhydrous silver trifluoromethanesulphonate (300 mg ) and dry triethylamine (0.14 ml) were dissolved in dry acetonitrile (0.18 ml) and the mixture was stirred at 25°C for 17h. The solution was evaporated to dryness and the residue was partitioned between 5% aqueous sodium bicarbonate and dichloromethane. The dichloromethane layer was washed with water, dried (Na₂SO₄), filtered and evaporated to dryness. The residue was chromatographed by preparative thin layer chromatography on 250 μ silica gel plates (sisc) using 45% acetone in toluene as the eluant to give 2'-O-acetyl-O-(1-ethoxyethyl)-(1→3)-rosaramicin (18 mg), MS; m/z 696 (MH⁺). Treatment of the latter with methanol (5 ml) at 25°C for 17h. afforded O-(1-ethoxyethyl)-(1→3)-rosaramicin.

EXAMPLE 20

O-β-D-Glύcopyranonyl-(1→3)-12,13-dehydro-12,13-deoxorosaramicin

Treat 2'-O-acetyl-12,13-dehydro-12,13-deoxorosaramicin with 2,3,4,6-tetra-O-acetyl-1-deoxy-1-(pyridyl-2-thio)-α- and -β-D-glucopyranoside (prepared as described in Example 1(d) starting from 2,3,4,6-tetra-O-acetyl-α- and -β-Dglucopyranose, which is prepared as described by J. Fiandor et. al., Synthesis, 1985, pp 1121-1123) in the presence of anhydrous, silver trifluoromethanesulphonate to give the β-D-glycoside, which is then deprotected as described in Example 8 to give the title compound.

Claims

What is Claimed is

1. A compound represented by the formula I:

wherein R₁ is a glycosyl group represented by the formula II:

wherein R_q and each R_t are independently hydrogen, hydroxy, acyloxy, loweralkoxy, aralkoxy, N- loweralkylamino-carbonyloxy, N-aralkylamino carbonyloxy, or arylsulfonyloxy (-OS0₂Ar) and R_s and R_w are independently hydrogen, lower alkyl or -CH₂OH; or represented by the formula IIA: wherein each R_a is independently hydrogen, lower alkyl, or CH₂OH and each R_b is independently hydrogen, hydroxy, acyloxy, loweralkoxy, aralkoxy, N- loweralkylaminocarbonyloxy, N-aralkylaminocarbonyloxy or arylsulfonyloxy and n is 1, 2, 3 or 4;

R₂ is hydrogen or an acyl group;

X is hydrogen, hydroxyl, an acyloxy group

wherein each R₂ is independently as defined hereinabove; Y is hydrogen, a formyl group, methyl,

wherein m is 0,1, or 2 and Q is independently CR₃R₄, NR₃, O, S, SO₂, CR₃OR₄,

wherein R₃ and R ₄ are independently hydrogen, lower alkyl, aralkyl, G-substituted aralkyl, aryl and G-substituted aryl wherein G is independently one or more of halogen, trifluoromethyl, lower alkoxy or (C₂ ^_C₇) alkanoyl; is a 12,13 double bond or a 12,13-oxo moiety; Z is hydrogen, hydroxy, an acyloxy group, a N,N-di(loweralkyl) amino group.

loweralkoxycarbonyloxy, aralkoxycarbonyloxy, N-loweralkylaminocarbonyloxy, and N-aralkylaminocarbonyloxy wherein R₂ is defined above and R₅ and R₆ are independently hydrogen, lower alkyl or acyl groups;

or a pharmaceutically acceptable acid addition salt thereof.

2. A compound of claim 1 wherein R₁ is an α-L-glycosyl group represented by formula I I

wherein R_q, R_s, R_t, and R_w are as defined in claim 1.

3. A compound of claim 1 wherein R₁ is α-L-cladinosyl or tetrahydropyranyl,

X is hydrogen, hydroxy, or

wherein R₂ is as defined in claim 2, Y is methyl, or formyl, Z is hydrogen, acyloxy, hydroxy, or

wherein R₂, R₅, and R₆ ar as defined in claim 1.

4. A compound of claim 1 which is O-(α-L-cladinosyl)-(1→3)-12,13-dehydro-20-dihydro-12,13,20-dideoxorosaramicin.

O-(α-L-cladinosyl)-(1→3)-12,13-dehydro-12,13-deoxorosaramicin,

O-(4'-O-acetyl- α-L-cladinosyl)-(1→3)-2''-O-acetyl-12,13-dehydro-20-dihydro-12,13,20-dideoxorosaramicin,

O-(4'-O-acetyl-α-L-cladinosyl)-(1→3)-2''-O-acetyl-12,13-dehydro-12,13-deoxorosaramicin, or O-tetrahydropyranyl-(1→3)-rosaramicin.

5. A compound of claim 1 wherein R₁ is wherein R₂ is as defined in claim 1, X is hydroxyl or an acyloxy group, Q is a 12,13 double bond and Z is

wherein R₂, R₅ and R₆ are as defined in claim 1

6. A compound of claim 5 wherein R₁ is

and R₂ is acetyl .

7. A compound of claim 1 which is 2'', 4'', 4''', tri-O-acetyl-19-deformyl-O-(4'-O-phenoxyacetyl-α-L-cladinosyl)-(1→3)-desmycosin, or

2'',4'',4'''-tri-O-acetyl-O-(4'-O-phenoxyacetyl-α-L-cladinosyl)-(1→3)-desmycosin, or

2'',4'',4'''-tri-O-acetyl-20-deoxo-20-dihydro-O-(4'-O-phenoxyacetyl-α-L-cladinosyl)-(1→3)-desmycosin, or

O - (α-L-cladinosyl)-(1→3)-19-deformyldesmycosin, or

O-(α-L-cladinosyl)-(1→3)-20-deoxo-20-dihydrodesmycosin, or

O -α-L-cladinosyl-(1→3)-desmycosin.

8. A pharmaceutical composition comprising a compound of any one of claims 1 to 7 in admixture with a pharmaceutically acceptable carrier therefor.

9. The use of a compound of any one of claims 1 to 7 for the preparation of a pharmaceutical composition useful for treating bacterial infection.

10. A method for making a pharmaceutical composition comprising mixing a compound of any one of claims 1 to 7 with a pharmaceutically acceptable carrier.