Synthesis of 6-Sulfonatomethyl Thioglycosides by Nucleophilic Substitution: Methods to Prevent 1→6 Anomeric Group Migration of Thioglycoside 6-<i>O</i>-Triflates
作者:Mihály Herczeg、Erika Mező、Dániel Eszenyi、László Lázár、Magdolna Csávás、Ilona Bereczki、Sándor Antus、Anikó Borbás
DOI:10.1002/ejoc.201300681
日期:2013.9
position of thioglycosides by nucleophilic displacement of the corresponding 6-O-triflate is described. The 1→6 migration of the anomeric group, which inevitably occurs through a bicyclic sulfonium ion intermediate, from conformationally flexible β-thioglycosides was prevented by using an α-thioglycoside or conformationally locked β-thioglycoside as the starting material. The thioglycoside 6-sulfonic
描述了通过相应 6-O-三氟甲磺酸酯的亲核置换将磺基甲基部分引入硫糖苷的主要位置。通过使用 α-硫糖苷或构象锁定的 β-硫糖苷作为起始材料,可以防止异头基团从构象灵活的 β-硫糖苷中不可避免地通过双环锍离子中间体发生 1→6 迁移。硫糖苷 6-磺酸在合成含肝素三糖的糖醛酸过程中表现出优异的 α 选择性。