SYNTHESIS OF 3',4',6'-TRIDEOXY-6'-FLUOROKANAMYCIN C, 3',4'-DIDEOXY-6'-C-(FLUOROMETHYL)KANAMYCIN B, AND THEIR 1-N-[(S)-4-AMINO-2-HYDROXYBUTANOYL] DERIVATIVES

3',4',6'-Trideoxy-6'-fluorokanamycin C (5) has been prepared by treatment of a protected kanamycin C derivative having the free 6-hydroxyl group with DAST, as the key step. Two 3',4'-dideoxy-6'-C-(fluoromethyl)kanamycin B's (17a and 17b) have been prepared from a 5'-C-aldehyde derivative of kanamycin C through a sequence of reactions involving nitromethane condensation and 6',7'-(N-tosylepimino)-ring opening with KHF2, as the key steps. 1-N-[(S)-4-Amino-2-hydroxybutanoyl] derivatives of 5 and 17a were prepared by coupling of the [(S)-4-amino-2-hydroxybutanoyl] residue to the 1-amino group of 5 and 17a by utilizing the zinc acetate-ethyl trifluoroacetate method. Biological effects caused by the introduction of the fluorine atom in these products were discussed based on the chemical character of fluorine.