Synthesis of tetra- and hexasaccharide fragments corresponding to the O-antigenic polysaccharide of Klebsiella pneumoniae
作者:San-Yong Zhu、Jin-Song Yang
DOI:10.1016/j.tet.2012.03.074
日期:2012.5
The preparation of linear tetra- (1) and hexasaccharides (2), containing the repeating unit [-> 3)-beta-Galf-(1 -> 3)-alpha-Galp-(1 -> ] present in the O-polysaccharide of the lipopolysaccharide of Klebsiella pneumoniae is described. The key step in their synthesis is the alpha-selective galactopyranosylation of 3-OH di- and tetrasaccharide acceptors (20 and 22) with a disaccharide trichloroacetimidate donor 19 in the presence of trimethylsilyl triflate in a diethyl ether-CH2Cl2 mixture as solvent. (C) 2012 Elsevier Ltd. All rights reserved.