PROCESS FOR THE CONVERSION OF NIDDAMYCIN TO LEUCOMYCIN A1 TO LEUCOMYCIN A3 AND 3-(O)-ALKANOYL ESTERS THEREOF AND TO CARBOMYCIN B AND 3-(O)-ALKANOYL ESTERS THEREOF AND PROVISION OF DIMETHYL ACETALS OF SAID COMPOUNDS

摘要

1502791 Niddamycin derivatives ABBOTT LABORATORIES 12 May 1975 [3 June 1974] 19950/75 Heading C2C Leucomycin A 1 is prepared by reducing niddamycin dimethyl acetal with NaBH 4 and CH 3 OH, chromatographically separating leucomycin A 1 dimethyl acetal from epimers thereof and hydrolysing the acetal with a solution of difluoroacetic acid in aqueous acetonitrile. 3-O-Alkanoyl(C 1-4 )-9-dihydroniddamycins B are prepared by alkanoylating niddamycin dimethyl acetal with pyridine-C 1-4 alkanoic anhydride, hydrolysing the resulting 2SP1/SP,3-di-OC 1-4 alkanoyl-niddamycin dimethyl acetal with aqueous methanolic NaHCO 3 , reducing the resulting 3-O-C 1-4 alkanoyl-niddamycin dimethyl acetal with an alkali metal borohydride and a non-aprotic solvent and hydrolysing the resulting 3-O-C 1-4 alkanoyl-9-dihydroniddamycin B dimethyl acetal in aqueous acetonitrile in the presence of a weak acid. 3-O-Alkanoyl- (C 1-4 )-niddamycins are prepared as above, but with omission of the reduction step. Niddamycin derivatives of the general formula wherein R is (H 1 OH) or O, R 1 is H or C 1-4 alkanoyl, R 2 is H or C 1-4 alkanoyl, provided that when R 2 is alkanoyl R 1 is also alkanoyl and the two groups are alike, and R 3 is bis-methoxymethyl, the compounds having the spatial configuration of 9-dihydroniddamycin B when R is (H 1 OH), are novel.