High yielding selective acetylation of only the anomeric hydroxyl of unprotected sugars is possible in aqueous solution using 2-chloro-1,3-dimethylimidazolinium chloride (DMC), thioacetic acid, and a suitable base. The reaction, which may be performed on a multi-gram scale, is stereoselective for sugars that possess a hydroxyl group at position-2, exclusively yielding the 1,2-trans products. The use of an iterative reagent addition procedure allows the use of sodium carbonate as the base, avoiding the formation of triethylammonium salts, which may hamper product purification. The glycosyl acetate products may be used as donor substrates for glycosidase-catalysed synthesis. The crude aqueous acetylation reaction mixture may also be used for this purpose.
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机译：使用2-氯-1,3-二甲基咪唑啉鎓氯化物（DMC），硫代乙酸和合适的碱，仅水溶液中未保护糖的异头羟基的高产率选择性乙酰化是可能的。该反应可以以克为单位进行，对于在2位具有羟基的糖具有立体选择性，仅产生1,2- trans 产物。使用迭代试剂添加程序可以使用碳酸钠作为碱，避免形成三乙铵盐，因为三乙铵盐可能会妨碍产品纯化。乙酸糖基酯产物可用作糖苷酶催化的合成的供体底物。粗的乙酰化水溶液反应混合物也可用于此目的。
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