Synthesis of a common trisaccharide fragment of glycoforms of the outer core region of the Pseudomonas aeruginosa lipopolysaccharide
作者:Bozhena S. Komarova、Yury E. Tsvetkov、Yuriy A. Knirel、Ulrich Zähringer、Gerald B. Pier、Nikolay E. Nifantiev
DOI:10.1016/j.tetlet.2006.03.045
日期:2006.5
β-glucosylation of an α-(1→4)-linked Glc-GalN3 unit, did not lead to the target trisaccharide backbone. Further O-deacetylation, azido group reduction and debenzylation of the protected trisaccharide precursor gave the corresponding trisaccharide amine. The latter structure was used in the synthesis of a series of trisaccharides bearing an acetyl group, an l-alanine or an N-acetylated l-alanine residue
报道了铜绿假单胞菌脂多糖外核心区糖型的常见三糖的首次合成。通过对β-(1→3)连接的6 - O-苄基-2-叠氮基-2-脱氧-3 - O -(- )进行高效的α-(1→4)-葡萄糖基化反应,可以制备出具有完全保护作用的三糖前体。2,3,4,6-四-O-乙酰基-β-d-吡喃葡萄糖基)-α-d-吡喃半乳糖苷。相反,糖基化的替代序列涉及与α-(1→4)连接的Glc-GalN 3的β-糖基化单位,没有导致目标三糖骨架。被保护的三糖前体的进一步O-脱乙酰基,叠氮基还原和脱苄基反应得到相应的三糖胺。后一种结构用于合成一系列三糖,其在GalN的C-2的氨基上带有乙酰基,1-丙氨酸或N-乙酰化的1-丙氨酸残基。