GB1567390A - Semi-synthetic oleandomycins - Google Patents

Description

(54) SEMI-SYNTHETIC OLEANDOMYCINS (71) We, PFIZER, INC., a Corporation organized under the laws of the State of Delaware, United States of America, of 235, East 42nd Street, New York, State of New York, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: Oiea'idomycfn, Its production in fermentation broths and its use as an antibacterial agent were first described in U.S. Patent 2,757,123, the disclosure of which is incorporated herein by reference. The naturally occurring compound is known to have the structure:

The conventionally accepted number scheme is shown at a variety of positions.

Several synthetic modifications of this compound are known, particularly those in which from one to three of the free hydroxyl groups found at the 2', 4" and 11-positions are esterified as acetyl esters. There are described in U.S. Patent 3,022,219 other modifications in which the acetyl group in the abovementioned esters is replaced with another, preferably unbranched alkanoyl group having from two to six carbon atoms or the trifluoroacetyl moiety.

Also known are semi-synthetic oleando mycins in which one or several of the hydro gens of the hydroxyl groups mentioned above are replaced with a tri(lower alkyl)silyl and preferablv a trimethyl-silyl group.

Thb invention is concerned with a semi synthetic oleandomycin of the formula:

and the non-toxic acid addition salts thereof, wherein R is selected from hydrogen and alkanoyl having two or three carbon atoms; Rl is selected from hydrogen, alkanoyl having two or three carbon atoms and tri (lower alkyl) silyl; and R2 is selected from hydrogen, alkanoyl having two or three carbon atoms, trifluoroacetyl and tri (lower alkyl) silyl.

This invention is also concerned with a Cy-cyclopropyl compound of the formula:

and the non-toxic acid addition salts thereof, wherein R is selected from hydrogen and alkanoyl having two or three carbon atoms; and Rl and R2 are selected from hydrogen, alkanoyl having two or three carbon atoms and tri (lower alkyl) silyl.

The term "lower alkyl" as used herein in reference to compounds of this invention refers to those branched and unbranched alkyl radicals of from one to six carbon atoms.

A compound of Formula II wherein R, Rl and R2 are selected from hydrogen and alkanoyl havlpg two or three carbon atoms is prepared from a compound of the formula:

wherein R, Rl and R2 are as defined above.

The reduction of the epoxide group to an exocyclic methylene group is accomplished by contacting a compound of Formula IV, dissolved in a reaction-inert water-miscible solvent, with lower valence state transition metal ions Cr+2, Tri+3 or V+2 in water.

Acetone, a C1C6 alkanol, tetrahydrofuran or mixtures thereof are preferred as the reaction-inert solvent and Cry12 is the preferred source of lower valence state transition metal ions.

In a preferred embodiment a solution of chromous chloride, prepared by treating a hydrochloric acid solution of chromium trichloride with zinc dust and mercuric chloride, is added to a flask under a carbon dioxide atmosphere along with simultaneous addition of an acetone solution of a compound of Formula IV wherein R, Rl and R2 are preferably hydrogen and/or acetyl. The additions are made over a period of 10 to 20 min. After stirring at room temperature for 20 to 40 minutes, water and ethyl acetate are added and the stirring continued for an additional 10 to 20 minutes. The ethyl acetate phase is separated, washed with water and sodium bicarbonate at pH 8.5, dried and concentrated under vacuum to yield a compound of Formula II.

A compound of Formula II wherein R and R1 are alkanoyl having two or three carbon atoms can be prepared with trifluoroacetoxy group at the 11-position by contacting a compound of Formula II where R2 is hydrogen and R and Rl are alkanoyl having two or three carbon atoms with trifluoroacetic anhydride at 5--10"C. in the presence of pyridine and allowing the reaction to proceed overnight at room temperature. The reaction mixture is concentrated to an oil and poured onto a mixture of ice and ethyl acetate. The aqueous phase is adjusted to pH 8.5 with aqueous sodium bicarbonate and the ethyl acetate phase separated, washed with water, dried and the solvent evaporated under reduced pressure.

A compound of Formula II wherein R and R1 are alkanoyl having two or three carbon atoms can be prepared with a tri (lower alkyl)silyloxy group at the 11-position by contacting a compound of Formula II where R2 is hydrogen and R and R1 are alkanoyl having two or three carbon atoms with a tri (lower alkyl)silyl chloride in the presence of imidazole and dimethylformamide at room temperature. After the addition of water and ethyl acetate and adjustment to pH 10.5, the organic phase is separated, washed, dried and evaporated under reduced pressure.

The best method for attaching a trifluoroacetyl or tri(lower alkyl) silyl group are those given above. The same procedures may be used to attach trifluoroacetyl or tri(lower alkyl)silyl to the 2' or to the 4" position.

These methods are applicable to the compounds of the Formula II and to the compounds of the Formula III (cyclopropyl compounds).

U.S. Patent No. 3 022 219 discloses that there is a certain order of selectivity of the attachment of ester groups to the 2', 4" and 11 position hydroxyls, that is, the R, R, and R, groups respectively. It is common knowledge in the art that an esterifying group will first attach to the 2' position (R group) and then to the 4" position (the Rl group) and lastly to the 11 position (R2 group).

Tbus the 11 position hydroxyl is the least reactive hydroxyL As will be shown later in the Eaaanples it is possible to selectively remove a group at the 2' position or at the 4' position. The esterifying group at the 2' position may be selectively cleaved by methanolysis, whereas the esterifying group St the 4" position is selectively removed by hydrolysis using sodium isopropoxide and isopropyl alcohol.

Using the above procedures for the attachment of trifluoroacetyl and tri(lower alkyl)siloxy groups and the procedures for selective cleavage of esterifying groups the remaining compounds of the Formula II can be prepared as follows:- A compound of the Formula II wherein R and R, are alkanoyl having two to three carbon atoms and R2 is trifluoroacetyl or tri(lower alkyl)silyl can be reacted with methanol to produce a compound of the Formula 1I wherein R is hydrogen, R1 is alkanoyl having two to three carbon atoms and R2 is trifluoroacetyl or tri(lower alkyl)- silyl. Reaction of this product with sodium isopropoxide and isopropyl alcohol produces a compound of the Formula II wherein R and R1 are hydrogen and R2 is trifluoroacetyl or tri(lower alkylsilyl.

A compound of the Formula lI wherein R and R, are alkanoyl having two to three carbon atoms and R2 is trifluoroacetyl or tri (lower alkyl)silyl can be reacted with sodium isopropoxide and isopropyl alcohol to produce a compound of the Formula II wherein R is alkanoyl having two to three carbon atom Rl is hydrogen and R2 is trifluoroacetyl or tri(lower alkylzsilyl.

By reacting a compound of the Formula II wherein R is alkanoyl having two q three carbon atoms and R, and R2 are hydrogen with a tri(lower alkyl)silyl chloride as de scamed above, a compound of the Formula II is produced wherein R is alkanoyl having two to three carbon atoms and R1 is tri(lower alkyl)silyl and R2 is hydrogen. Further reaction of this product with a tri(lower- alkyl)silyl chloride produces a compound of the Formula II wherein R is alkanoyl having two to three carbon atoms and R, and R are tri(lower alkyl)silyl. Reaction of this pro- duct with methanol produces a compound of the formula II wherein R is hydrogen and Rl and R2 are tri(lower alkyl)silyl.

By reacting a compound of the Formula II wherein R is alkanoyl having two to three carbon atoms, Rl is tri(lower all:yl)silyl and R2 is hydrogen with methanol, a compound of the Formula II is produced wherein R arld R2 are hydrogen and R, is tri(lower alkyl)silyl, or alternatively by reacting with a trifluoroacetic anhydride, as described above, instead of methanol a compound of the Formula II is produced wherein R is alkanoyl having two to three carbon atoms, Rl is tri(lower alkyl)silyl and R2 is trifluoroatyl.

Further reaction of this compound with methanol produces a compound of the Formula II wherein R is hydrogen, R, is tri(lower alkyl)silyl and R2 is trifluoroacetyl.

By reacting a compound of the Formula II wherein R and R2 are alkanoyl having two to three carbon atoms and Rl is hydrogen with a tri(lower alkyl)silyl chloride as described above a compound of the Formula II is produced wherein R and R2 are alkanoyl having two to three carbon atoms and Rl is tri(lower alkyl)silyl. Further reaction of this product with a methanol yields a compound of the Formula II wherein R is hydrogen, R1 is tri(lower alkyl) silyl and R2 is alkanoyl having two to three carbon atoms.

A cyclopropyl moiety is formed by contacting a compound of Formula II wherein R is alkanoyl having two to three carbon atoms; R, is selected from hydrogen, alkanoyl having two or three carbon atoms and tri (lower alkyl)silyl; and K2 is selected from alkanoyl having two or three carbon atoms and tri(lower alkyl)silyl with cooling in icewater with at least a substantially equivalent amount of dimethylsulfoxonium methylide in a reaction-inert solvent and then allowing the mixture to come to room temperature and maintaining contact until the reaction is substantially complete. A preferred reactioninert solvent is tetrahydrofuran, dimethylsulfoxide or a mixture thereof. In a preferred embodiment equimolar amounts of trimethylsulfoxonium iodide and 50% oil dispersion of sodium hydride are placed in a flask to which is added dimethylsulfoxide over a 5 to 10 minute period with cooling in an ice/ water bath. The reaction mixture is allowed to come to room temperature until the evolution of hydrogen ceases. A solution of a compound of Formula II and dimethylsulfoxide is added dropwise and the reaction allowed to proceed at room temperature for about an hour. The solution is poured into water/ethyl acetate and the aqueous phase adjusted to pH 9.0. The organic phase is separated, washed with water, dried and evaporated to dryness under reduced pressure.

A compound of the Formula III wherein R and Rl are alkanoyl having two to three carbon atoms can be prepared with a hydroxyl group at the 11 position by contacting a compound of the Formula III wherein R and R1 are alkanoyl having two to three carbon atoms and R2 is tri(lower alkyl ) silyl with aqueous tetrahydrofuran, adjusting the pH to 2.0 with acid, stirring for one hour, adjusting the pH to 6.9 and then evaporating off the tetrahydrofuran under reduced pressure. The resulting material is added to a mixture of ethyl acetate and water and the pH adjusted to 9. The ethyl acetate phase is then separated, washed with water and saturated Narc1, dried, filtered and evaporated under reduced pressure. Similarly, a compound of the Formula III wherein R and R1 are hydrogen, or R and R1 are each different and are hydrogen or alkanoyl having two to three carbon atoms and K2 is hydrogen can be prepared from a compound of the Formula III wherein R and R1 are as described above and R2 is tri(lower alkyl)silyl.

A compound of the Formula III wherein R is alkanoyl having two to three carbon atoms, R1 is tri(lower alkyl) silyl and R2 is hydrogen can be prepared from a compound of the Formula III wherein R is alkanoyl having two to three carbon atoms and Rl and R2 are hydrogen, by the silylation procedure given above for a compound of the Formula II. On further reacting the product so formed with methanol a compound of the Formula III wherein R is hydrogen, R1 is tri (lower alkyl)silyl and R2 is hydrogen is produced.

A compound of the Formula III wherein R is hydrogen, Rl is hydrogen, alkanoyl having two to three carbon atoms, or tri (lower alkyl)silyl and R2 is alkanoyl having two to three carbon atoms or tri(lower alkyl)silyl can be prepared by methanolysis from a compound of the Formula III wherein R is alkanoyl having two to three carbon atoms and R1 and R2 are as above.

The pharmaceutically-acceptable acid addition salts of the semi-synthetic oleandomycins of the present invention may be prepared by contacting a solution of a compound of Formula II or Formula III in a suitable solvent such as acetone with a stoichiometric equivalent of a mineral acid such as hydrochloric, hydrobromic, phosphoric or sulfuric acid; an organic acid selected from aspartic, citric, tartaric, gluconic, succinic and stearic acid; or an alkyl sulfuric acid such as lauryl sulfuric acid. The salt precipitates after the neutralization reaction or, if necessary, after partial evaporation of the reaction solution.

The product may be recovered by filtration, centrifugation or lyophilization.

The oleandomycin compounds of the present invention are effective in inhibiting the growth of microorganisms, especially Grampositive microorganisnis. The high activity against Gram-positive organisms shown by these compounds is contrasted in some respects with the lower activity against Gramnegative organisms. The following table illustrates the in vitro antibiotic spectrum of the compounds of the instant invention. The tests were run according to the "minimum inhibitory concentration" (MIC) procedure of Ericsson and Sherris (H. M. Ericsson and J. C. Sherris, Acta. Patrol. Microbiol. Scand.

Suppl., 217B 64 (1971)1.

TABLE I.

MIC Values (mcg./ml.) of some Semi Synthetic Oleandomycins

Staph. aureus Staph. aureus E. coli Klebsiella pn. Salm. typhm.

Compound R R1 R2 01A00 5* 01A400R* B. subtilis* 51A266+ 53A009+ 58D009+ II Ac H Ac 3.12 > 200 3.12 #200 > 200 > 200 II H H H 6.25 25 - > 200 > 200 II Ac Ac Ac 25 200 - > 200 > 200 > 200 O II Ac Ac CF3C 25 200 25 > 200 > 200 > 200 III Ac H Ac 0.20 3.12 0.78 > 200 > 200 > 200 III H H H 0.20 1.56 0.39 > 200 > 200 > 200 III Ac Ac Ac 1.56 12.5 3.12 > 200 > 200 > 200 III Ac Ac Me3Si 3.12 > 200 12.5 > 200 > 200 > 200 * = Gram-positive.

+ = Gram-negative.

AC = Acetyl.

The ability of the compound of the present invention to protect against in vivo infections was determined by subcutaneous or oral administration to mice infected with Staph. aureus 01A005. Using the test method described by Retsema [J. A. Retsema et al., Antimicr, Agents and Chemother., 9 975 (1976)], it was determined that, in particular, compounds II and III wherein R, R1 and R2 are each hydrogen both gave protection against infection which was comparable to natural oleandomycin.

For effective prophylactic and anti-infectious in vivo use, the semi-synthetic oleandomycin compounds of the present invention may be administrated either alone or in combination with a pharmaceutically-acceptable carrier and by both the oral and parenteral routes. The ultimate choice of route and dose is made by the attending physician and is based upon the patient's unique condition.

However, the usual dosage for administration to humans may be in the range of approximately 500-2000 mg. per day, and preferably in about one to four doses. However, this dosage may vary somewhat with the weight of the subject being treated; in general, about 10-40 mg/kg. of body weight per day may be employed.

In order to use the compounds of this invention, they may be combined with inert pharmaceutical excipients such as lactose, mannitol and starch, and formulated into dosage forms such as tablets and capsules.

For parenteral administration, these com pounds may be formulated with an inert, parenterally acceptable vehicle such as water, saline, sesame oil, and propylene glycol.

These various pharmaceutical dosage forms are compounded by methods well known to the pharmacist's art.

The following Examples illustrate the invention: EXAMPLE I.

8,8a - Deoxy - 2',4" - Di - O - acetyl- oleandomycin A five liter, 3-necked round bottom flask was charged with zinc dust (200 g) and mercuric chloride (20 g). After the solids were mixed well, 1N HCl (500 ml) was added and the mixture was stirred vigorously for 15 min. The aqueous supernatant liquid was removed and fresh 1N HC1 (500 ml) added and the flask placed under a carbon dioxide atmosphere. A filtered solution of chromium trichloride (1 kg in 1300 ml of 1N HCI) was added rapidly to the zinc amalgam. The mixture was stirred under a carbon dioxide atmosphere for 1 hr during which time a light blue color developed, indicating the presence of chromous chloride (CrC12). Stirring was discontinued after 1 hr and the zinc amalgam allowed to settle to the bottom of the flask.

A solution of 2',4" - diacetyloleandomycin hydrochloride (500 g) in acetone (3.5 1) and water (1.75 1) was placed in a dropping funnel attached to a 12 liter, 3 necked round bottom flask equipued with an overhead-mechanical stirrer. To this flask was added, under a carbon dioxide atmosphere and with stirring, the solution of 2',4"-di- acetyloleandomycin hydrochloride and the previously prepared solution of chromous chloride. The solutions were added simultaneously at such a rate that both finished being added at the same time. The addition took about 12 minutes.

After 35 min. of stirring at room temperature, water (21) and ethyl acetate (21) were added to the reaction mixture and stirring continued for 15 min. The ethyl acetate was separated and washed with water (1600 ml).

The ethyl acetate was separated and the aqueous extracts combined and washed with fresh ethyl acetate (2 1). The ethyl acetate layer was separated and washed with water (1.7 1). The organic phase was separated and the aqueous washes combined and treated with sodium chloride (1500 g). The additional ethyl acetate which separated was showed off and combined with the other ethyl acetate extracts. Water was added to the combined ethyl acetate extracts and ad justed to pH 8.5 with sodium bicarbonate.

The organic layer was separated, washed with water and saturated sodium chloride and dried over anhydrous sodium sulfate. Filtration and evaporation of the solvents under reduced pressure afforded a white solid which was crystallized from ethyl acetate/heptane to give the title compound (237 g, mp 184 1860C.) Elemental Analysis C H N Calculated 61.96 8.67 1.85 Found 61.78 8.54 1.87 Spectral Data NMR(CDCl2): y=5.61(1H)bS; 5.53(1H)bS; 3.36(3H)S; 2.26(6H)S; 2.10(3H)S; 2.06(3H)S.

IR(CHCI,): 5.75, 5.90 and 6.15vex W(CH,OH): 225m,u; e=5338 I/mole In a similar fashion, the other 2',4"-acyl - esters of 8,8a - Deoxyoleandomycin may be prepared from the corresponding 2',4"-acyl esters of the natural epoxide compound, having two or three carbon atoms in the acyl groups.

EXAMPLE II.

8,8a - Deoxy - 2',4",1 1 - Triacetyloleando mycin A solution of 2',4",1 1 - triacetyloleandomycin (500 g) in acetone (3.25 1) and water (1.75 1) was treated with a solution of chromous chloride [prepared by the method of Example I from chromium trichloride (1000 g), zinc dust (200 g) and mercuric chloride (20 g) 1 in a carbon dioxide atmosphere as described in Example I. The final ethyl acetate extracts (2500 ml) were concentrated to 800 ml and 3 volumes of heptane added and the crystallization allowed to proceed overnight to yield in two crops the title compound (426 g, m.p. 132--134"C).

Elemental Analysis C H N Calculated 61.71 8.46 1.76 Found 61.59 8.42 1.72 Spectral Data NMR(CDCl,): 8=5.86(1H)bS; 5.61(1H)bS; 3.33(3H)S; 2.26(6H)S; 2.06(6H)S; 2.01(3H)S.

IR(CHC1,): 5.70, 5.90, 6.00 and 6.17.

UV(CH3OH): 228my e=5927 I/mole.

In a similar fashion, the other 2',4",11-acyl esters of 8,8a - deoxy - oleandomycin, except those with a trifluoroacetoxy or a tri-(lower altyl)silyloxy group at the 11-position, are prepared from the corresponding 2',4",1 1 - acyl esters of the natural epoxide compound having two or three carbon atoms in the acyl group(s).

EXAMPLE III.

8,Sa - Deoxy - 2' - Acetyloleandomycin A solution of 2' - acetyloleandomycin (29.2 g) in acetone (200 ml) and water (100 ml) was mixed with a solution of chromous chloride [prepared from chromium trichloride (50 g), zinc dust (10 g) and mercuric chloride (1 g) by the method of Example I] in a carbon dioxide atmosphere as described in Example I. The final ethyl acetate extracts were concentrated to dryness under reduced pressure and the residue crystallized from ether/petroleum ether, followed by recrystallization from ethyl acetate/petroleum ether to give the title compound (8.4 g m.p.

183.5-1850C).

Elemental Analysis C H N Calculated 62.16 9.02 1.95 Found 61 97 8.91 2.01 Spectral Data NMR(CDC1,): 8=5.63(lH)bS; 5.58(1H)bS; 3.431(3H)S; 2.36(6H)S 2.08 (3H) S.

IR(CHCl8): 5.78, 5.90, 5.95 and 6.12 UV(CH3OH): 224m #=4468 1/mole.

In a similar fashion, the other 2'-acyl esters of S,8a - deoxy - oleandomycin are prepared from the corresponding 2'-acyl esters of the natural epoxide compound having two or three carbon atoms in the acyl group.

EXAMPLE IV.

8,8a-Deoxy-Oleandomycin A solution of oleandomycin (5.0 g) in water (25 ml), adjusted to pH 3.5 with 1N HCl, was mixed with a solution of chromous chloride [chromium trichloride (13 g), zinc dust (8 g) and mercuric chloride (700 mg), prepared by the method of Example I] in a carbon dioxide atmosphere. About half-way through the mixing acetone (20 mlj was added to the mixture and the additions continued. After 45 min. of stirring at room temperature, methylene chloride (100 ml) was added and the pH was adjusted to 8.5 with 8N sodium hydroxide. The organic phase was separated and the aqueous layer extracted with a second portion of methylene chloride (100 ml). The methylene chloride extracts were combined, washed with water (100 ml), saturated sodium chloride (200 ml) and dried over anhydrous sodium sulfate and evaporated under reduced pressure. The residue was crystallized from chloroform by displacement with heptane to give the title compound (2.28 g, m.p. 120-1230C).

Spectral Data NMR(CDCl3): 8=5.63(1H)bS; 5.56(1H)bS; 3.41(3H)S; 2.30(6H)S.

UV(CH,OH): 223 m,u; e=3900 1/mole.

EXAMPLE V.

8,8a - Deoxy - 2',4" - Diacetyl - 11 - Tri fluoroacetyloleandomycin To a flame-dried 1 liter; 3-necked round bottom flask equipped with a magnetic stirrer, dropping funnel and drying tube was added 8,8a - deoxy - 2',4" - diacetyloleandomycin (200 g) and trifluoroacetic anhydride (400 ml) at 5--100C. Pyridine (42.6 ml) was added over a 5 min. period and the reaction allowed to proceed overnight at room temperature. The reaction mixture was concentrated to an oil under reduced pressure and poured onto a mixture of ice and ethyl acetate. The pH was adjusted to pH 8.5 with aqueous sodium bicarbonate and the ethyl acetate phase separated, washed with water and saturated sodium chloride and dried over anhydrous sodium sulfate.

The solvent was evaporated under reduced pressure and the resulting roam crystallized from ethyl acetate/heptane to give the title compound (136 g., m.p. 169--172"C).

Elemental Analysis C H N Calculated 57.80 7.57 1.64 Found 57.79 7.50 1.62 Spectral Data NMR(CDCl,): =6.08(1H)S; 5.91(1H)S; 3.41(3H)S; 2.36(6H)S; 2.16(6H)S.

IR(CHCl2): 5.75, 5.85, 5.90 and 6.10E.

In a similar fashion, the other 2',4"-diacyloleandomycins of the present invention may be converted into the corresponding 2',4"diacyl - 11 - trifluoroacetyloleandomycins having two or three carbon atoms in the acyl group.

EXAMPLE VI.

8,8a - Deoxy - 2',4" - Diacetyl - 11 - Tri fluoroacetyloleandomycin A solution of 8,8a - deoxy - 2',4" - diacetyloleandomycin (1.0 g) in 50 ml of benzene was treated with 0.20 ml of trifluoracetic anhydride and 0.11 ml of pyridine.

The solution was stirred at room temperature for 90 minutes and poured into water.

Sodium bicarbonate solution was added to pH 8.5 and the organic layer separated, washed with water and saturated sodium chloride and dried over anhydrous sodium sulfate. Evaporation of the solvent under reduced pressure gave 8,8a - deoxy diacetyl - 11 - trifluoracetyloleandomycin, identical by spectroscopic and thin layer chromatographic analysis with a specimen prepared by the method of Example V.

EXAMPLE VII.

8,8a-Deoxy-2',1 1-Diacetyloleandomycin To a stirred solution of 8,8a - deoxy 2',4",11 - triacetyloleandomycin in isopropyl alcohol (50 ml) at room temperature under nitrogen was added a solution of sodium isopropoxide in isopropyl alcohol (17.8 ml, 0.176M). After 3.5 hr another portion of the sodium isopropoxide solution (17.8 ml, 0.176M) was added and stirring continued for 1 hr at room temperature. The pale yellow solution was poured into water and extracted with ethyl acetate. The organic phase was separated, washed successively with water and saturated sodium chloride, dried over sodium sulfate, filtered and evaporated. The resulting foam was crystallived from ethyl acetate:hexane to give the title compound (2.35 g, m.p. 117-1190C).

Spectral Data NMR(CDC13): 8=5.96(1H)bS; 5.73(1H)bS; 3.45(3H)S; 2.33(6H)S; and 2.10(3H)S.

In a similar fashion, the other 2',1 1- diacyloleandomycins of the present invention may be prepared from the corresponding 2',4",11 - triacyloleandomycins having two or three carbon atoms in the acyl group.

EXAMPLE VIII.

8,8a - Deoxy - 2',4" - Diacetyl - 11 - ri- methysilyloleandomycin In a flame-dried 100 ml, 3-necked round bottom flask equipped with magnetic stirrer and drying tube, a suspension of 8,8a - deoxy 2',4" - diacetyloleandomycin (20 g), and characteristic peaks in the nmr: (CDCl3) γ=2.35 (3H)S; 2.26 (6H)S; 2,10 (6H)S; 2.03 (3H)S; 0.60 (4H)M.

EXAMPLE X.

8,8a - Deoxy - 8,8a - methylene - 11 Acetyloleandomycin A solution of 12.0 g (14.8 mmoles) of 8,8- deoxy - 8,8a - methylene 2',4",11triacetyloleandomycin in 300 ml of methanol wis treated with 719 mg (17.1 mmoles) of lithium hydroxide monohydrate and the dear colorless solution was stirred at room tem perarre under nitrogen overnight The solu- Ii- was evaporated to dryness under reduced pressure and the resulting white foam was then up in a mixture of water and ethyl acetate and adjusted to pH 9. The organic phase was separated, washed with water and saturated sodium chloride, dried over anhydrous sodium sulfate, filtered and evaporated to yield a white foam which was crystallized from acetone/heptane giving 8.8 g of X,8a - deoxy - 8,8a - methylene - 11acetyloleandomycin, m.p. 121.5-123.5C, and showing the following characteristic peaks in the nmr: (CDCl3) γ=4.20 (1H) D; 3.40 (3H) S; 2.28 (6H) S; 2.03 (3H) S; 0.53 (4H) M; EXAMPLE XI.

S,8a - Deozy - 8,8a - methylene - 11 Acetyloleandomycin A solution of 8,8a - deoxy - 8,8amethylene - 2',11 - diacetyloleandomycin (1.3 gm, 1.16 mmoles) in methanol was red overnight, evaporated to dryness under reduced pressure and the residue crystallized from acetone/heptane to give 800 mg of 8,8a - deoxy - 8,8a - methylene - 11 - acetyloleandomycin, m.p. 123-125 C, identical by thin layer chromatography and nmr with material prepared by the lithium hydroxide procedure (Example X).

EXAMPLE XII.

8,8a - Deoxy - 8,8a - Methylene - 4",11 Diacethyloleandomycin A sahdbn of 8,81 - deoxy - 8,8a- methylene - 2',4",11 - triacetyloleandomycin (1.5 g. 1.85 mmoles) in methanol was stirred evaporated to dryness under reduced pressure and the residue crystallized from ether/heptane to give 1.3 g of 8,8adeoxy - 8,8a - methylene - 4",11 - diacetyloleandomycin, m.p. 159-161.5 C, which shows the following characteristic peaks in the nmr.

(CDCL3) γ=3.35 (3H) S; 2.40 (6H) S; 2.09 (3H) S; 2.04 (3H) S; 0.58 (4H) M.

EXAMPLE XIII.

8,8a - Deoxy - 8,8a - Methylene - 2',11 Diacetyloleandomycin In a flame-dried 200 ml three-necked flask equipped with a dropping funnel, mag netic stirrer and a positive-pressure nitrogen inlet were combined 16.4 g (74.8 mmoles) of trimethylsulfoxonium iodide and 3.4 g (74.8 mmoles) of a 50% oil dispersion of sodium hydride. The solids were mixed well and 43.2 ml of DMSO was added via the. dropping funnel. After one hour, when the evolution of hydrogen had stopped, the sus pension was cooled to 5-100C and a solu tion of 22.6 g (30 mmoles) of 8,8a - deoxy 2',11 - diacetyloleandomycin in 32 ml of THF and 16 ml of DMSO was added over a 10 minute period. The suspension was stirred at room temperature for 90 minutes and poured into 300 ml of water and ex tracted with two 300 ml portions of ethyl acetate. The organic extracts were washed with water and a saturated solution of sodium chloride, dried over anhydrous sodium sulfate, filtered, and evaporated to dryness under reduced pressure. The residue was crystallized from ether to give 8.9 g of 8,8a- deoxy - 8,8a- methylene - 2',11 - diacetyl oleandomycin, identical by thin layer chromatography and nmr with material pre pared by the sodium isopropoxide procedure on 8,8a - deoxy - 8,8a - methylene - 2',4",11triacetyloleandomycin (Example XIV).

EXAMPLE XIV.

8,8a - Deoxy - 8,8a - Methylene - 2',11 Diacetyloleandomycin In a 12 liter three-necked round bottom fla*, flame-dried and equipped with a mechanical stirrer and positive pressure nitrogen inlet was dissolved 306 g (0.376 mmoles) of 8,81 - deoxy - 8,81 - methylene 2',4",11 - triacetyloleandomycin in 3 liters of isopropyl alcohol. To this solution was added over a 10 minute period 1230 ml (0.376 mmoles) of a 0.3 M solution of sodium iso propoxide in isopropyl alcohol. After about 30 minutes, 3 liters of water was added, the solution adjusted to pH 7.0 and concentrated under reduced pressure to approximately one half volume, poured into ethyl acetate and readjusted to pH 9.5. The organic layer was separated, washed with water and a saturated solution of sodium chloride, dried over sodium sulfate, filtered and evaporated under reduced pressure. The resulting foam was dissolved in 2 liters of benzene and treated with 7.0 ml of acetic anhydride. After one hour at room temperature the solution was treated with an additional 7.0 ml of acetic anhydride and after stirring for 45 minutes more was poured into 2 liters of water, and the pH adjusted to 7.0 with solid sodium tricarbonate and to 9.5 with 4N sodium hydroxide. The organic layer was separated, washed with water and a saturated solution of sodium chloride, dried over anhydrous sodium sulfate, filtered and evaporated to dryness under reduced pressure. The residue was crystallized from ether to give 159 g of 8,8a - deoxy - 8,8a - methylene - 2',11diacetyloleandomycin, m.p. 159--162"C, and showing the following characteristic peaks in the nmr: (CDCl,) y=3.43 (3H) S; 2.28 (6H) S; 2.10 (3H) S; 2.03 (3H) S; 0.56 (4H) M.

EXAMPLE XV.

8,8a - Deoxy - 8,8a - Methylene - 8,8a Cyclopropyl - 2',4" - Diacetyloleandomycin A solution of 8,8a - deoxy - 8,8amethylene - 2',4" - diacetyl - 11 - trimethylsilyloleandomycin (4.6 g, 5.46 mmoles) in 100 ml of 30% aqueous tetrahydrofuran, adjusted to pH 2.0 with acid, was stirred for one hour at room temperature, the pH adjusted to 6.9 and the tetrahydrofuran evaporated under reduced pressure. The resulting material was added to a mixture of ethyl acetate and water and the pH adjusted to 9. The ethyl acetate phase was separated, washed with water and saturated sodium chloride, dried over sodium sulfate, filtered and evaporated under reduced pressure to a white foam (4.0 g). Chromatography of 3.4 g of this material on 120 g of silica gel, eluting with the solvent system benzene/ acetone (4:1), gave 2.5 g of 8,8a - deoxy8,8a - methylene - 2',4" - diacetyloleandomycin as a white foam, homogeneous in the TLC systems ethyl acetate/acetone (3:1) and carbon-tetrachloride/diethylamine (9:1) and carbon tetrachloride/diethylamine (9:1) (Brinkman silica gel plates) and exhibiting the following peaks in the nmr: (CDCl,) y=5.45 (1H) M; 3.35 (3H) S; 2.25 (6H) S; 2.08 (6H) S; 0.65 (4H) M.

EXAMPLE XVI.

8,8a - Deoxy - 8,8a - Methylene - oleando mycin To a solution of 19 g (22.5 mmoles) of 8,8a - deoxy - 8,8a - methylene -2',4/'- diacetyl - 11 - trimethylsilyloleandomycin in 1 liter of methanol in a flame-dried 2 liter single necked round bottom flask equipped with magnetic stirrer and nitrogen inlet was added 3.12 g (22.5 mmoles) of potassium carbonate and the solution stirred at room temperature overnight. This solution was adjusted to pH 2.0 with 1N hydrochloric acid (-50 ml) and the solution stirred at room temperature for 40 minutes. The solution was adjusted to pH 6.9 and the methanol evaporated under reduced pressure. The residue was distributed between ethyl acetate/water, the pH adjusted to 9.0 and the organic layer separated, washed with water and saturated sodium chloride, dried over sodium sulfate, filtered and evaporated to a white foam (12 g). This material was chromatographed on 300 g of silica gel, eluted with chloroform/methanol (19:1) and the desired fractions combined ~ and evaporated to give 5.6 g of 8,8a - deoxy8,8a - methylene - oleandomycin as a white foam. This material is homogeneous in the TLC (Brinkman silica gel plates) systems ethyl acetate/ methanol (1:1), carbon tetrachloride/diethylamine (9:1) and chloroform/ methanol (4:1), and exhibits the following characteristic peaks in the nmr: (CDCl,) r=5.45 (1H) ; 4.93 (1H) M; 4.13 (1H) D; 3.40 (3H) S; 2.26 (H) S; 0.63 (4H) M.

EXAMPLE XVII.

8,8a - Deoxy - 8,8a - Methylene - 2' - Acetyl oleandomycin To a stirred solution of 8,8a - deoxy - 8,8amethylene - oleandomycin (184 mg, 0.26 mmoles) in 18 ml of benzene was added 27.8s1 (0.295 mmoles) of acetic anhydride.

The solution was stirred at room temperature under nitrogen for two hours, poured into a mixture of water and ethyl acetate and adjusted to pH 9. The organic layer was separated washed with water and saturated sodium chloride, dried over sodium sulfate, filtered and evaporated under reduced pressure to give 173 mg of 8,8a - deoxy8,8a - methylene - 2' - acetyloleandomycin showing the following characteristic peaks in nmr: (CDCl2) y=5.45 (1H) M; 3.38 (3H) S; 2.25 (6H) S; 2.05 (3H) S; 0.65 (4H) M.

EXAMPLE XVII I.

8,8a - Deoxy - 8,8a - methylene - 2',4" - Di acetyl - 11 - Trimethylsilyloleandomycin In a flame-dried, 75 ml, three-necked round bottom flask equipped with a magnetic stirrer, serum stopper and positive nitrogen hook-up were mixed 1.20 g (5.46 mmoles) trimethylsulfoxonium iodide and 262 mg (5.46 mmoles) of 50% oil dispersion sodium hydride. The mixture was cooled in an ice/ water bath and 13 ml of dimethylsulfoxide was added via a syringe over a one minute period. Vigorous hydrogen evolution was noted. The cooling bath was removed and stirring continued for 45 minutes to yield the ylid as a pale tan solution. This solution was cooled in an ice/water bath and a solution of 3.62 g (4.37 mmoles) of 8,8a - deoxy - - diacetyl - 11 - trimethylsilyloleando- mycin in 22 ml of tetrahydrofuran (sieve dried) was added via a syringe, washing in with an additional 8 ml of dry tetrahydrofuran. The addition was made over a one minute period after the cooling bath was removed and the white suspension stirred at room temperature for one hour and forty minutes. The mixture was poured into 100 ml of water and 100 ml of ethyl acetate and the aqueous phase was separated. The organic phase was washed with one volume of water and one volume of saturated sodium chloride, dried over anhydrous sodium sulfate, filtered and evaporated under reduced pressure to yield 3.3 g of white foam. This material is homogeneous in the chromatography systems ethyl acetate/acetone (3:1) and carbon tetra chloride/diethylamine (9:1) on Brinkman silica gel plates. It exhibits the following characteristic peaks in nmr: (CDCla) y=3.40 (3H) S; 2.33 (6H) S; 2.15 (3H) S; 2.13 (H) S; 0.58 (4H) M; 0.15 (9H) S.

EXAMPLE XIX.

8,8a - Deoxy - 8,8a - Methylene - 4" Acetyloleandomycin A solution of 1.0 g (1.3 mmoles) of 8,8a- deoxy - 8,Sa - methylene - 2',4" - diacetyloleandomycin in 100 ml of methanol was stirred overnight at room temperature. The solvent was evaporated under reduced pressure to give 1.0 g of 8,8a - deoxy - 8,8amethylene - 4" - acetyloleandomycin as a white foam homogeneous in the thin layer chromatography systems ethyl acetate/acetone (3:1) and carbon tetrachloride/diethylamine (9:1) (Branlcnan silica gel plates) and showing the following peaks in the nmr: (CDCl,) y=5.43 (1H) M; 3.33 (3H) S; 2.26 (6H) S; 2.06 (3H) S; 0.63 (4H) M.

Claims (8)

1. WHAT WE CLAIM IS:1. A compound of the formula

   and the non-toxic acid addition salts thereof, wherein R is selected from hydrogen and alkanoyl having two or three carbon atoms; R, is selected from hydrogen, alkanoyl having two or three carbon atoms and tri- (loweralkyl) silyl; and R2 is selected from hydrogen, alkanoyl having two or three carbon atoms, trifluoroacetyl and tri(lower alkyl)silyl.
2. 2. The compound of claim 1 wherein R and R1 are acetyl and R2 is acetyl, trifluoroacetyl or trimethylsilyl.
3. 3. A compound of the formula

   and the non-toxic acid addition salts thereof, wherein R is selected from hydrogen and alkanoyl having two or three carbon atoms; and R1 and R2 are selected from hydrogen, alkanoyl having two or three carbon atoms and tri-(lower alkyl)silyl.
4. 4. A compound of claim 3 wherein R and R1 are hydrogen and R2 is hydrogen or acetyl.
5. 5. A process for preparing a compound of the formula

   wherein R, R1 and R2 are selected from hydrogen and alkanoyl having two or three carbon atoms, which comprises contacting a compound of the formula

   wherein R, R1 and R2 are as defined above, disolved in a water-miscible, reaction-inert solvent with lower valence state transition metal ions selected from Cr+2, Ti+3 and V+2 in water.
6. 6. The process of claim 5 wherein said water-miscible, reaction-inert solvent is selected from acetone, a C1-C6 alkanol, tetrahydrofuran and mixtures thereof.
7. 7. A process for preparing a compound of the formula

   wherein R is alkanoyl having two or three carbon atoms; R1 is selected from hydrogen, alkanoyl having two or three carbon atoms and tri-(lower alkyl) silyl; and R2 is selected from alkanoyl having two or three carbon atoms and tri-(lower alkyl) silyl, which comprises contacting a compound of the formula

   wherein R, R1 and are as defined above, in a reaction-inert solvent with cooling in ice/water with at least a substantially equivalent amount of dimethylsulfoxonium methyl- ide and then allowing the mixture to come to room temperature and maintaining contact until the reaction is substantially complete.
8. 8. The process of claim 7 wherein the reaction-inert solvent is selected from di- methylsulfoxide, tetrahydrofuran and mixtures thereof