Synthesis of the Forssman pentasaccharide and terminal tetra-, tri-, and di-saccharide fragments
作者:Ulf Nilsson、Asim K. Ray、Göran Magnusson
DOI:10.1016/0008-6215(94)90011-6
日期:1994.1
The 2-(trimethylsilyl)ethyl (TMSEt) beta-glycosides of the Forssman pentasaccharide [alpha-D-GalNAc-(1-->3)-beta-D-GalNAc-(1-->3)-alpha-D-Gal- (1-->4)-beta-D-Gal-(1-->4)-D-Glc] and the terminal tetrasaccharide, as well as the methyl glycosides 1 and 2 of the terminal di- and tri-saccharides, were synthesised by silver trifluoromethanesulfonate-promoted alpha-glycosylation of suitably protected mono-
福斯曼五糖[α-D-GalNAc-(1-> 3)-β-D-GalNAc-(1-> 3)-alpha-D-的2-(三甲基甲硅烷基)乙基(TMSEt)β-糖苷Gal-(1-> 4)-beta-D-Gal-(1-> 4)-D-Glc]和末端四糖,以及末端di-和tri-的甲基糖苷1和2通过三氟甲磺酸银促进适当保护的单糖,二糖,三糖和四糖醇与3,4,6-三-O-乙酰基-2-叠氮基-2-脱氧-α-糖基化的α-糖基化反应合成糖D-吡喃半乳糖基溴化物,然后除去保护基。用三氟乙酸-二氯甲烷除去Forssman五糖和末端四糖的异头TMSEt基团,得到相应的半缩醛糖4和6。