A new strategy in oligosaccharide synthesis using lipophilic protecting groups: synthesis of a tetracosasaccharide
作者:Vince Pozsgay
DOI:10.1016/s0957-4166(99)00553-4
日期:2000.1
The use of lipophilic, acyl-type protecting groups in the synthesis of higher-membered oligosaccharides is described by the example of oligosaccharides corresponding to the O-specific polysaccharide (O-SP) of Shigella dysenteriae type 1. Thus, O-stearoylated and O-lauroylated l-rhamnose and d-galactose precursors, respectively, were synthesized and were combined together with a 2-azido-2-deoxy-d-glucopyranosyl
保护基团在更高元的寡糖的合成中使用的亲脂性,酰基型的由对应于O型特异性多糖的(O-SP)的寡糖的实例描述的志贺氏痢疾杆菌型1。因此,ö -stearoylated和ö分别合成了月桂酰化的l-鼠李糖和d-半乳糖前体,并与2-叠氮基-2-脱氧-d-吡喃葡萄糖基供体结合在一起,形成了O-SP的完全保护的脂化重复单元。该模块与另一种含有常规封闭基团的四糖缩合。通过吸附到反相吸附剂上以纯净的形式分离所得的脂化八糖,该糖可以被醇类溶剂选择性地解吸。随后使用常规保护的四糖模块作为糖基供体的链延长提供了寡糖,直至和包括四糖。所提出的方法可以大大减轻与保护寡糖中间体的常规硅胶色谱纯化有关的困难,并使用比用于硅胶色谱的溶剂便宜的环保溶剂。还提出了一种新的高效方法,该方法使用三氟甲磺酸scan作为催化剂来合成碳水化合物的缩醛和环状原酸酯。