摘要:
A mild and general procedure for the synthesis of alpha-thioglycosides from glycopyranoses is described. The method involves the treatment of pyranose reductive sugar with sodium hydride, carbon disulfide, and p-nitrobenzoyl chloride, as a key step, to yield p-nitrobenzoyl-alpha-D-thioglycopyranose intermediates with high stereoselectivity, in a one-pot-two-step process. The interest of the strategy highlights a direct stereoselective access to ether-protected 1-thiol-alpha-D-glycopyranose derivatives (Gal, Glc, and Man) from pyranoses in the absence of anomeric 'Lewis acid' promoters. (c) 2006 Elsevier Ltd. All rights reserved.