Anomerization and transglycosylation reactions of permethylated methyl d-glycopyranosides
作者:Chang Kiu Lee、Eun Ju Kim、In-Sook Han Lee
DOI:10.1016/0008-6215(93)84183-7
日期:1993.2
Abstract The anomerization reactions of permethylated methyl d -glycopyranosides in the presence of various Lewis acid catalysts, such as Me3SiOTf, Me3SiOMs, BF3·OEt2, or TiCl4 were examined in dichloromethane solution. β Anomers of the glycosides anomerized to the α anomer very rapidly, but the anomerizations in the opposite direction were slower. Transglycosylation reactions of the glycosides in the
摘要研究了在二氯甲烷溶液中,在各种路易斯酸催化剂(如Me3SiOTf,Me3SiOMs,BF3·OEt2或TiCl4)存在下,全甲基化甲基d-吡喃吡喃糖苷的异构化反应。糖苷的β端基异构体非常快地异构化为α端基异构体,但反方向的端基异构化则较慢。在相似的催化剂和乙醇的存在下,糖苷的转糖基化反应优选产生具有大多数底物的α端基异构体。在α-甘露糖苷的情况下未观察到异构化,这可能是因为在平衡时α-异构体被强烈青睐。然而,转糖基化发生了。