Glycosylation with 2′-thio-S-acetyl participation

The reaction of 1,2,3,4,6-penta-O,S,O,O,O-acetyl-2-thio-β-d-glucopyranose with glycosyl acceptors in the presence of trimethylsilyl triflate leads to the β-disaccharides exclusively, owing to especially avid anchimeric assistance by the 2-thio-S-acetyl group. Optional reductive removal of SAc with Ra–Ni gives the corresponding 2′-deoxy-β-disaccharides.