Derivatives of 3-carboxyrifamycin S and SV and process for their preparation

摘要

New compounds being derivatives of 3-carboxyrifamycin S and SV are prepared by oxidation of cyanohydrin of 3-formylrifamycin S to 3-(cyanocarbonyl)rifamycin S, condensation with a compound of formula HR (an alcohol, an amine or an substituted hydrazine) and, optionally, reduction of the derivative of 3-carboxyrifamycin S so obtained to the corresponding SV form. Alternatively 3-(cyanocarbonyl)rifamycin S may be converted to the SV form before condensing with the compound HR.