反应详情

A solution of 1-phenyl-1-trimethylsiloxyethylene (25.0 g, 130 mmol) in absolute ether (400 mL) was cooled to −78° C., and malonyl dichloride (6.40 mL, 65.0 mmol) was added dropwise to the resulting solution by using a dropping funnel. The mixture was gradually heated to room temperature, stirred at room temperature (5 to 10° C.) for 14 hours, and further stirred at 30° C. for 24 hours. The thus-produced yellow precipitate was filtered and washed with absolute ether to give the target 4-hydroxy-6-methyl-2-pyrone (8.40 g, 67%) as a yellow solid.

1. stirringfurther stirred at 30° C. for 24 hours
2. filtrationThe thus-produced yellow precipitate was filtered
3. washwashed with absolute ether