Phosphorus oxychloride → 3,4-Dihydro-4,4-dimethyl-2H-pyran-2-one

Participants

Reaction Conditions

Reaction Steps

A solution of 16.98 g (0.10 mole at 93% purity) of ethyl 3,3-dimethyl-5-oxopentanoate and 9.44 g (0.062 mole) of phosphoryl chloride in 10 g of sulfolane was added to 250 g of sulfolane and the whole heated to 200° C. in an oil bath during 50 minutes. The reaction mixture was stirred at 200° C. for 1 hour, then subjected to distillation to give 9.71 g of 3,4-dihydro-4,4-dimethyl-2H-pyran-2-one in 2 fractions: fraction 1, 7.49 g, bp 55° C./400 Pa (3 mm Hg), 95.9% purity (glpc); fraction 2, 2.22 g, bp 55°-120° C./400 Pa, 71.1% purity (glpc).

Provenance & Evidence