3-O-demethyl-2,3-di-epi-fortimicins and 3-O-demethyl-3-epi-fortimicins

Syntheses of the 3-O-demethyl-2,3-di-epi-fortimicins A and B and the 3-O-demethyl-3-epi-fortimicins A and B have been accomplished in processes the key steps of which were solvolyses of 4-N-acetyl-3-O-demethyl-3-O-methanesulfonylfortimicin derivatives. Antibacterial activities of the new antibiotics are reported.