4- DEMETHOXYDOXORUBICIN -AND DAUNOMYCIN-4- CARBOXYLIC ACIDS, ESTERS THEREOF THEIR PRERARATION AND PHARMACEUTICAL COMPOSITIONS CONTAINING

摘要

4-substituted anthracyclinones of formula (I) wherein R represents a hydrogen atom or a straight or branched alkyl, alkenyl or alkynyl group having from 1 to 10 carbon atoms, are intermediates in the preparation of antitumor anthracycline glycosides of formula (IX): wherein R is as defined above and R₁ is a hydrogen atom or a hydroxy group, and pharmaceutically acceptable salts thereof.