groups. Removal of the anomeric TMSEt group of the globotetraoside and of the terminal trisaccharide, using trifluoroacetic acid-dichloromethane, gave the corresponding hemiacetal sugars 8 and 3. The TMSEt glycoside of the terminal trisaccharide was converted, via the 1-acetate, into the corresponding isobutyl (4) and 3-butylsulfonyl-2-[(butylsulfonyl)methyl]propyl (5) glycosides and into the TMSEt thioglycoside
球四糖[β-D-GalNAc-(1-> 3)-alpha-D-Gal-(1-> 4)-beta-D-Gal-的2-(三
甲基甲
硅烷基)乙基(
TMSEt)β-糖苷(1-> 4)-D-Glc]和末端三糖,以及末端二糖的
甲基α-糖苷1,是由
三氟甲磺酸银促进适当保护的半
乳糖苷,galabioside和globotrioside的β-糖基化合成的醇与3,4,6-三-O-
乙酰基-2-
脱氧-2-邻
苯二甲
酰亚胺基-β-D-
吡喃半
乳糖苷
氯,然后除去保护基。用
三氟乙酸-
二氯甲烷除去三糖四糖苷和末端三糖的异头
TMSEt基团,得到相应的
半缩醛糖8和3。末端三糖的
TMSEt糖苷通过1-
乙酸盐转化,