Halide-mediated regioselective 6-O-glycosylation of unprotected hexopyranosides with perbenzylated glycosyl bromide donors
作者:Dominika Alina Niedbal、Robert Madsen
DOI:10.1016/j.tet.2015.11.059
日期:2016.1
couplings were completely selective for both glucose and galactose donors and acceptors as long as the stannylene acetal of the acceptor was soluble in dichloromethane. This gave rise to a number of 1,2-cis-linked disaccharides in reasonable yields. Mannose donors and acceptors, on the other hand, did not react in the glycosylation under these conditions.
已经用二丁基氧化锡作为导向剂研究了在2,3,4,6-未保护的己吡喃糖苷中6-位的区域和立体选择性糖基化。使用全苄基化的六吡喃糖基溴化物作为供体,并且通过四丁基溴化铵促进糖基化。只要受体的亚锡乙缩醛可溶于二氯甲烷,偶联对于葡萄糖和半乳糖供体和受体都是完全选择性的。这以合理的产率产生了许多1,2-顺式连接的二糖。另一方面,在这些条件下,甘露糖供体和受体在糖基化中不反应。