Studies on Aminosugars. XXXII. Synthesis of 3′, 4′-Dideoxykanamycin B

Abstract

Abstract Penta-N-ethoxycarbonylkanamycin B (1) prepared from kanamycin B was treated with 2,2-dimethoxypropane in DMF to give a 3′,4′;4″,6″-di-O-isopropylidene derivative (3). Subsequent benzoylation afforded a 2″-O-benzoyl derivative (4), Removal of the isopropylidene groups from 4 followed by controlled isopropylidenation afforded the corresponding 4″,6″-O-isopropylidene derivative (5), which was then transformed to a 3′,4′-di-O-mesyl derivative (6). Treatment of 6 with sodium iodide and zinc dust in DMF gave the desired 3′,4′-unsaturated derivative (7). Hydrogenation and removal of the protecting groups gave the title compound. The 3′,4′-dideoxykanamycin B expectedly showed remarkable activity against kanamycin-resistant bacteria as well as sensitive strains.