1-Aryl-substituted 2,3,3-trifluoro-1-propenyl p-toluenesulfonate 1 was smoothly hydrolyzed in a mixed solvent of dimethyl sulfoxide-water (1 : 1) in the presence of sodium hydroxide at 80 °C to afford the corresponding aryl α-monofluoromethyl ketones 2 in fair to good yields.