A facile preparation of peracylated α-aldopyranosyl chlorides with thionyl chloride and tin tetrachloride

Aldopyranose peracetates react with thionyl chloride and tin tetrachloride, producing the corresponding peracylated aldopyranosyl chlorides in very good to excellent yields (88–100%) with exclusive α-anomeric selectivity and short reaction times. The use of peracylated sugars as the substrate in large scale reactions also proceeds in high yield.