Synthesis of unsymmetrical 3,6-branched Man5 oligosaccharide: a comparison between one-pot sequential glycosylation and stepwise synthesis
摘要:
An expeditious three-component, one-pot sequential glycosylation protocol has been developed for the preparation of 3,6-branched unsymmetrical mannopentaose (Man5), employing a mannose trisaccharide donor, a mannose monosaccharide donor and a mannose monosaccharide acceptor. The high efficiency of this one-pot procedure was demonstrated by comparison study with a stepwise synthesis using the same three building blocks. (C) 2014 Elsevier Ltd. All rights reserved.
Synthesis of Branched Man5 Oligosaccharides and an Unusual Stereochemical Observation
作者:Nardos Teumelsan、Xuefei Huang
DOI:10.1021/jo7013824
日期:2007.11.1
[GRAPHICS]Branched mannopentaoses, were synthesized through two routes. While assembly from the nonreducing end to the reducing end was more convergent with fewer intermediate steps, two diastereomers were obtained. On the other hand, synthesis from the reducing end to the nonreducing end yielded the mannopentaose with the desired stereochemistry as a single isomer. Our results suggest that it is still challenging to reliably predict stereochemical outcome of a glycosylation reaction. It is necessary to thoroughly characterize anomeric configurations of newly formed glycosidic linkages in complex oligosaccharide synthesis.