3'-Hydroxyesorubicin. Synthesis and antitumor activity

A novel route to 4'-deoxy anthracycline analogues has been developed starting from previously unavailable, optically active 4,6-dideoxy-hex-1-enitol 9. Coupling of daunomycinone (11) or 14-O-tert-butyldimethylsilyladriamycinone (12) with glycosyl chloride 10 in Koenigs-Knorr condition gave mainly alpha anomers, which were successfully deblocked to final 3'-deamino-4'-deoxy-3'-hydroxydaunorubicin (7) and 3'-deamino-3'-hydroxyesorubicin (8). Analogues were evaluated in vitro against P388 and L1210 leukemia and M5076 cells and in vivo against P388 leukemia. Compared with doxorubicin (1), 3'-hydroxyesorubicin (8) showed in vitro similar cytotoxic potential and in vivo higher antitumor activity.