Glycosyl trichloroacetylcarbamate: a new glycosyl donor for O-glycosylation
摘要:
Glycosyl trichloroacetylcarbamates, readily obtained by reacting 1-hydroxy sugars with trichloroacetylisocyanate, have been found as excellent glycosyl donors, and the corresponding O-glycosides are formed in good to excellent yields with a fairly good degree of selectivity. (c) 2005 Elsevier Ltd. All rights reserved.
Efficient catalytic and stereoselective glycosylation was achieved by activating a glycosyl N-trichloroacetylcarbamate with a catalytic amount of Lewis acid in the presence of a glycosyl acceptor and 5A molecular sieves. Catalytic one-pot dehydrative glycosylation of a 1-hydroxy carbohydrate was achieved stereoselectively by reaction with trichloroacetyl isocyanate, followed by activation with a catalytic
An efficient sequential one-pot glycosylation has been developed with glycosyl trichlorocarbamate and trichloroacetate activated by the same Lewis acid and enabled by a change in reaction temperature. The act-selective glycosylation was achieved using glucose, galactose, and mannose substrates after investigation into the reactivities of the two types of glycosyl donors. Sequential one-pot dehydrative glycosylation, including in situ preparation of glycosyl donors followed by generation of two glycosyl bonds, provided three types of trisaccharide. (C) 2011 Published by Elsevier Ltd.
Glycosyl trichloroacetylcarbamate: a new glycosyl donor for O-glycosylation
作者:K. Jayakanthan、Yashwant D. Vankar
DOI:10.1016/j.carres.2005.07.024
日期:2005.12
Glycosyl trichloroacetylcarbamates, readily obtained by reacting 1-hydroxy sugars with trichloroacetylisocyanate, have been found as excellent glycosyl donors, and the corresponding O-glycosides are formed in good to excellent yields with a fairly good degree of selectivity. (c) 2005 Elsevier Ltd. All rights reserved.