Synthesis of tetra- and pentasaccharides corresponding to the capsular polysaccharide of Streptococcus pneumoniae type 9A&L, 9N and 9A
作者:Mia Alpe、Stefan Oscarson
DOI:10.1016/s0008-6215(03)00271-4
日期:2003.11
Two tetrasaccharides, alpha-D-GlcAp-(l --> 3)-alpha-D-Galp-(1 --> 3)-beta-D-ManpNAc-(1 --> 4)-beta-D-Glcp and alpha-D-GlcAp-(1 --> 3)-alpha-D-Glcp(1 --> 3)-p-D-ManpNAc-(1 --> 4)-beta-D-Glcp (protected form), and a pentasaccharide, alpha-D-Glcp-(1 --> 4)-alpha-D-GlcAp-(1 --> 3)-alpha-D-GalP-(1 --> 3)-beta-D-ManpNAc-(1 --> 4)-beta-D-Glcp have been synthesised from 2-aminoethyl glycoside trisaccharide acceptors in a linear approach via consecutive alpha-glycosylations. Ethyl thioglycosides were used as glycosyl donors and DMTST in Et2O or NIS/TfOH in CH2Cl2 were employed as promoters. (C) 2003 Elsevier Ltd. All rights reserved.