Two routes to enantiomerically pure 3-aminoinosose derivatives

Abstract

Epoxidation with hydrogen peroxide/benzonitrile of (2 S)-(2,4/3)-2,3,4-tribenzyloxycyclohex-5-enone ethylene acetal ( 13), obtained from methyl 2,3,4-tri- O-benzyl-6-deoxy-α- d- xylo-hex-5-enopyranoside ( 9), gave the (2,4/3,5,6)-5,6-anhydride 14 which, with sodium azide in 2-methoxyethanol, gave the (2,4,5/3,6)-5-azido-6-hydroxy derivative 15. (2 S)-(2,4/3)-2,3,4-Tribenzyloxy-6-phenylsulphonylcyclohex-5-enone ethylene acetal ( 18) was also prepared from 13 by reaction in sequence with N-chlorosuccinimide-thiophenol, m-chloroperbenzoic acid, and potassium tert-butoxide. Treatment of 18 with aqueous ammonia gave the inosamine derivative (2 S)-2,4,5/3,6)-5-amino-2,3,4-tribenzyloxy-6-phenylsulphonylcyclohexanone ethylene acetal ( 20). Compounds 15 and 20 offer a novel access to 3-aminoinosose derivatives and suggest routes to enantiomerically pure compounds such as hydroxyvalidamine, validamine, and inosadiamines related to streptamine and deoxystreptamine.