| abstract |
Compounds of the formula <IMAGE> I wherein X and X' form C=O or C=NOR, R is selected from the group consisting of hydrogen, heterocycle, alkyl, alkenyl, alkynyl, all optionally substituted, <IMAGE> Ra and Rb are hydrogen or a hydrocarbon group or form together with the nitrogen a heterocycle, or with A forms a 9-N, 11-O ring, and X' is hydrogen, -Y and Y' have the same definition as X and X', b is hydrogen or OR4, R4 is hydrogen or forms together with A a carbonate or a carbamate, A forms with C a double bond or A is OR'4, R'4 is hydrogen or forms together with B a carbonate or <IMAGE> R2 is alkyl or -CONH2, -CONHCOR11 or -CONHSO2R11, R11 is a hydrocarbon up to 18 carbon atoms, R3 is hydrogen, <IMAGE> and Z is hydrogen or a carboxylic acid remainder and their non-toxic, pharmaceutically acceptable acid addition salts, their preparation and intermediates useful as antibiotics. |