Synthesis of methyl glycosides of some α-isomalto oligosaccharides specifically deoxygenated at position C-2

Methyl α-isomaltoside and methyl α-isomaltotrioside analogues specifically deoxygenated at position C-2 of various glucopyranosyl units were synthesized by condensation of either 6-O-acetyl-3-O-benzoyl-4-O-benzyl-1-O-tert-butyldimethylsilyl-2-deoxy-β-d-arabino-hexopyranose (trimethylsilyl triflate mediated) or 6-O-acetyl-2,3,4-tri-O-benzyl-α-d-glucopyranosyl chloride (mediated by silver carbonate and silver triflate) with suitably blocked derivatives of methyl α-d-glucopyranoside, its 2-deoxy analogue, or methyl 2′-deoxy-α-isomaltoside.