Stereoselective synthesis of an aminocyclopentitol analog of alpha-L-fucose via an allylic bromohydrin

摘要

Selective opening of allylic epoxide 4 with lithium bromide in acetic acid provides an allylic bromohydrin (5). Chemo- and stereoselective hydrogenation of the corresponding benzyl carbamate 6 and intramolecular cyclization gives, after deprotection, (1R, 2R, 3R, 4R, 5R) 4-amino-5-methyl-cyclopentane-1,2,3-triol 3, an analog of alpha-L-fucose. This synthetic sequence provides one of the few stereoselective approaches to alpha-configurated aminocyclopentitols. [References: 29]