Synthese von β-l-rhamnosidisch verknüpften oligosacchariden des lipopolysaccharides aus Shigella flexneri sero-typ 6
作者:Hans Paulsen、Wolfram Kutschker
DOI:10.1016/0008-6215(83)88004-5
日期:1983.8
O -β- l -rhamnopyranosyl-(1→2)- l -rhamnopyranose ( 21 ) is described. The latter structure has been proposed as the repeating unit of the O-specific side-chain of the lipopolysaccharide obtained from Shigella flexneri Serotype 6. The key-intermediate was 4- O -acetyl-2- O -allyl-3- O -benzyl-α- d -rhamnopyranosyl bromide, which was first linked to benzyl 3,4-di- O -benzyl-α- l -rhamnopyranoside,
摘要三糖O-β-1-鼠李吡喃糖基-(1→4)-O-β-1-鼠李吡喃糖基-(1→2)-1-鼠李吡喃糖(14)和四糖O-(2-乙酰胺基- 2-脱氧-β-d-吡喃并吡喃糖基)-(1→2)-O- [β-1-鼠李糖吡喃糖基-(1→4)]-O-β-1-鼠李糖吡喃糖基-(1→2)-l-鼠李糖吡喃糖(21)被描述。已提出后者的结构作为得自弗氏志贺氏菌血清型6的脂多糖的O-特异性侧链的重复单元。关键中间体为4-O-乙酰基-2-O-烯丙基-3-O-苄基。首先与苄基3,4-二-O-苄基-α-1-鼠李糖吡喃糖苷连接的-α-d-鼠李糖吡喃糖基溴化物得到封闭的β-连接的二糖。将其O-脱乙酰化,并在O-4'处与2,3,4-三-O-苄基-α-1-鼠李糖基吡喃糖基溴偶联,得到苄基O-(2,3,4-三-O-苄基-β-1-鼠李糖基吡喃糖基)-(1→4)-O-(2-O-烯丙基-3-O-苄基-β-1-鼠李糖吡喃糖基)-(1→2)-3