Bromodimethylsulfonium bromide (BDMS) mediated dithioacetalization of carbohydrates under solvent-free conditions

A variety of diethyl dithioacetals of sugars can be prepared in very good yields by the reaction of various monosaccharides with ethanethiol in the presence of 3 mol % bromodimethylsulfonium bromide (BDMS) at 0–5 °C. Similarly, dipropyl dithioacetal derivatives can also be obtained in good yields using propanethiol under identical reaction conditions. These dithioacetal derivatives were characterized by per-O-acetylation using silica gel-supported perchloric acid. The significant features of the present protocol are good-to-excellent yields, mild, clean, and solvent-free reaction conditions. This method is extremely suitable for the large-scale preparation of dithioacetal derivatives of various sugars.

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