Synthesis of the globotetraose tetrasaccharide and terminal tri- and di-saccharide fragments
The 2-(trimethylsilyl)ethyl (TMSEt) β-glycosides of globotetraose [β-d-GalNAc-(1 → 3)-α-d-Gal-(1 → 4)-β-d-Gal-(1 → 4)-d-Glc] and the terminal trisaccharide, as well as the methyl α-glycoside 1 of the terminal disaccharide, were synthesised by silver trifluoromethanesulfonate-promoted β-glycosylation of suitably protected galactoside, galabioside, and globotrioside alcohols with 3,4,6-tri-O-acetyl-