Synthesis of 1-O-(Methylthio)thiocarbonyl Sugar Derivatives Bearing Acyl Protective Groups Using Phase Transfer Catalysis Methods

2,3,4,6-Tetra-O-acetyl-D-glucopyranose (1) was successfully transformed to an anomeric mixture of 2,3,4,6-tetra-O-acetyl-1-O-(methylthio)thiocarbonyl-D-glucopyranose (2) by liquid - liquid and solid - liquid phase transfer methods. Similar anomeric free sugar derivatives bearing acetyl or benzoyl protective groups were also smoothly converted to the corresponding 1-O-(methylthio)thiocarbonyl dervatives. Thermal rearrangement 1-O-(methylthio)thiocarbonylfuranose derivatives proceeded well to give 1-S-methylthiocarbonyl-1-thiofuranose derivatives.