New approach to C-aryl glycosides starting from phenol and glycosyl fluoride. Lewis acid-catalyzed rearrangement of O-glycoside to C-glycoside

C-Glycosidation of phenols is achieved by treatment of glycosyl fluoride with phenolic compound under Lewis acidic conditions, which leads to initial O-glycoside formation followed by rearrangement to C-congener. Cp2HfCl2-AgClO4 is particularly effective for this conversion.