Heteroanthracycline antitumor analogs

A compound of the formula ##STR12## X.sub.1 is C.dbd.O;

• X.sub.2 is S;
• X.sub.3 is selected from the group consisting of
• S and
• SO.sub.2
• R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.8 are independently selected from group consisting of
• hydrogen,
• C.sub.1-16 alkyl, and
• C.sub.1-16 alkoxy,
• R.sub.7 is hydrogen;
• R.sub.6 is a monosaccharide of the formula ##STR13## wherein R.sub.9 and R.sub.10 are each hydrogen R.sub.11 is selected from the group consisting of
• amino, and
• trifluoro C.sub.1-16 acylated amino;
• and
• R.sub.12 is selected from the group consisting of
• hydrogen,
• hydroxyl or its tetrahydropranyl ether,
• halogen, and
• benzoate which may be unsubstituted or substituted by nitro,
• inclusive of the 1S and 1R isomers and the pharmaceutically acceptable salts thereof.