Synthesis of Tetrasaccharide Repeating Unit of the O‐Antigen from Enterohemorrhagic Escherichia coli O157 in the form of its 2‐(trimethylsilyl)ethyl Glycoside
摘要:
Two alpha-linked disaccharide derivatives, ethyl 3,4,6-tri-O-acetyl-2-azido-2-deoxy-alpha-D-galactopyranosyl-(1 -> 2)-4-azido-3-O-benzyl-4,6-dideoxy-1-thio-alpha-D-mannopyranoside (10) and 2-(trimethylsilyl)ethyl 3-O-acetyl-4-O-benzoyl-2-O-benzyl-alpha-L-fucopyranosyl-(1 -> 4)-2,3-di-O-benzyl-6-O-tert-butyldiphenylsilyl-beta-D-glucopyranoside (16), were prepared from appropriate monosaccharide synthons. The disaccharide 16 was deacetylated and debenzoylated to afford the acceptor 17, which was allowed to react with the donor 10 to afford a tetrasaccharide derivative 18. This tetrasaccharide was transformed in three steps into 21, the desired repeating unit of the antigen from enterohemorrhagic E. coli type O157.
作者:Chengli Zong、Zhongzhen Li、Tiantian Sun、Peng Wang、Ning Ding、Yingxia Li
DOI:10.1016/j.carres.2010.04.006
日期:2010.7
Two types of sulfated octyl tetra- to octaoligofucosides with different sulfation patterns were synthesized employing a combination of stepwise elongation and convergent strategies in which trichloroacetimidates and thioglycosides were selected as the glycosyl donors. (C) 2010 Elsevier Ltd. All rights reserved.