Efficient Dehydrative Glycosylation Promoted Bismuth(III) Trifluoromethansulfonate and Synthesis of Trehalose Analogs

Abstract

Trehalose has been widely found in nature, and its medical use is recently expected. We investigated the synthesis of several non-reducing disaccharides as trehalose mimics by the Lewis acid-promoted dehydrative glycosylation. The dehydrative glycosylation using 2,3,4,6-tetra-O-benzyl-D-glucopyranose was catalyzed by 20 mol% Bi(OTf)₃ as the activator and the trehalose derivative was successfully obtained in good yield. Moreover, we investigated the synthesis of the trehalose mimics into which the 1-C-methyl-D-hexopyranose derivatives were incorporated.1 The 1-C-methyl-D-hexopyranosylation to several aldopyranoses was efficiently catalyzed in the presence of only 5 mol% Bi(OTf)₃, and several kinds of trehalose mimics of non-reducing disaccharides were obtained in good yields. Our Bi(OTf)₃-catalyzed dehydrative glycosylation was also applicable to the synthesis of glycosides using ordinary alcohols.

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