Synthesis of 3'-deoxy-3'-fluorokanamycins A and B active against resistant bacteria.

Sir: Kanamycins are inactivated by enzymes of resistant bacteria phosphorylating or adenylylating the 3', 4' or 2"-hydroxyl groups' 21 , among which the 3'-hydroxyl group is most frequently modified. Syntheses of 3'-deoxykanamycin A3), 3',4'-dide-oxykanamycin B4) (dibekacine), and other deoxy derivatives of kanamycins and related aminogly-coside antibiotics were the major solution"" in order to overcome the inactivation by resistant bacteria. In this communication we describe the synthesis of useful derivatives by replacing the 3'-hydroxyl group with a fluorine atom to avoid the above modifications by resistant bacteria**. For the first approach, we prepared 3'-deoxy-3'-fluorokanamycins A (1) and B (2).