Stereoselective synthesis of α-glucosides by neighbouring group participation via an intermediate thiophenium ion
摘要:
The use of a 2-O-(thiophen-2-yl)methyl protecting group allows highly stereoselective alpha-glucosylation of a trichloroacetimidate donor: increased stereoselectivity, presumably arising from the intramolecular formation of a transient intermediate thiophenium ion, correlates with increased bulk of the glycosyl acceptor. (C) 2009 Elsevier Ltd. All rights reserved.
Protecting Group Dependence of Stereochemical Outcome of Glycosylation of 2-<i>O</i>-(Thiophen-2-yl)methyl Ether Protected Glycosyl Donors
作者:Andrew J. A. Watson、Stewart R. Alexander、Daniel J. Cox、Antony J. Fairbanks
DOI:10.1002/ejoc.201600071
日期:2016.3
A series of glycosyl donors possessing a (thiophen-2-yl)methyl ether protecting group at position 2 were synthesised and the effect of the protecting group pattern of other hydroxyls on the stereochemical outcome of glycosylation was investigated. Studies revealed optimal α-selectivity for glycosylation using a fully armed tri-benzylated donor, whilst other protecting group patterns were significantly