Synthesis of 4-demethoxyanthracyclines carrying a lipophilic alkanoyl group at the C9-position.

Abstract
By employing various novel reactions developed in our synthetic studies on 4-demethoxy-adriamycin and 4-demethoxydaunorubicin, three examples of the title compounds (7a-c) were prepared from (R)-2, 5, 12-trihydroxy-1, 2, 3, 4-tetrahydro-6, 11-naphthacenedione-2-carboxylic acid (9). While 7a-c showed marked cytotoxicity against P388 in vitro, it was found that 7a (carrying a nonanoyl group at the C9-position) was ineffective against P388 in vivo.