Novel Dehydrative Ulycosylation by Using Acid Anhydride and TMSCIO4

Novel dehydrative glycosylation with I-hydroxy sugars as glycosyl donors was achieved. Combination of trifluoroacetic anhydride or trichloroacetic anhydride as dehydrating agents with TMSCIO4 as Lewis acid afforded desired glycosides in good yields. t-ButyIdiphenylsilyl and trichloroethoxycarbonyl groups at the 6-position of donors enhance oc-selectivity of the glycosylation,