Galabiosyl donors; efficient synthesis from 1,2,3,4,6-penta-O-acetyl-β- -galactopyranose
作者:Jörgen Ohlsson、Göran Magnusson
DOI:10.1016/s0008-6215(00)00154-3
日期:2000.10
1,2,3,4,6-Penta-O-acetyl-beta-D-galactopyranose was transformed into phenyl 2,3,4,6-tetra-O-benzyl-1-thio-beta-D-galactopyranoside (5) and 4-methoxyphenyl 2,3,6-tri-O-benzoyl-beta-D-galactopyranoside (8) in 73% (two steps) and 58% (three steps) yield, respectively. Glycosylation of the acceptor 8 with donor 5 using N-iodosuccinimide-trimethylsilyl trifluoromethanesulfonate as promoter furnished the
1,2,3,4,6-五-O-乙酰基-β-D-吡喃半乳糖转化为苯基2,3,4,6-四-O-苄基-1-硫代-β-D-吡喃半乳糖苷(5 )和4-甲氧基苯基2,3,6-三-O-苯甲酰基-β-D-吡喃半乳糖苷(8)的产率分别为73%(两步)和58%(三步)。使用N-碘代琥珀酰亚胺-三甲基甲硅烷基三氟甲磺酸盐作为促进剂,用供体5对受体8进行糖基化,以95%的产率提供了galabioside 9(8.8 g)。以高产率提供的进一步转化可适合用作合成含半乳糖的低聚糖中的糖基供体的异源活化的加拉比苷(硫糖苷(1),三氯乙酰亚胺(2)和溴糖(3))。此处报道的几种化合物是结晶的,极大地简化了纯化过程。