4-Demethoxy-4-hydroxydaunorubicin 6-methyl ether and 11-methyl ether, two active isomers of daunorubicin

The preparation of two isomers of daunorubicin, one having a completely chelated dihydroxyanthraquinone chromophor (III) and one have having such a chromophor in a emichelated form (IV), is reported. The former is as active as daunorubicin, the latter shows a considerable activity, however at much higher doses.