GENERAL PROCEDURE: In a dry Schlenk tube, sodium hydride (6.0 mmol) was stirred with ethyl trifluoroacetate (6.0 mmol) in tetrahydrofuran (5 mL) for 10 minutes at room temperature under argon protection. Subsequently, a solution of enolizable ketone (5.0 mmol) in tetrahydrofuran (5 mL) was slowly added dropwise to the above mixture at 0°C and under argon atmosphere. The reaction solution was stirred at a set temperature for 2 to 6 hours before being cooled again to 0°C and the reaction was quenched with 6 mL of a 1 mol/L hydrochloric acid solution. After continued stirring for 15 minutes, the mixture was neutralized with saturated sodium bicarbonate solution. After conventional post-treatment steps, the residue was purified by silica gel column chromatography to give the target product trifluoromethyl alkyl ketone.
