Butyryl chloride → 2-Butyryl-5,5-dimethyl-3-hydroxy-4-phenylcyclohex-2-ene-1-one

Participants

Reaction Steps

Triethylamine (5.2 g) was added dropwise to a stirred solution of 5,5-dimethyl-4-phenyl cyclohexane-1,3-dione (10.8 g) and n-butyryl chloride (5.3 g) in methylene chloride (100 ml). After stirring at ambient temperature for a further 2 hours, the reaction solution was washed with water and brine and dried over anhydrous magnesium sulphate. The methylene chloride was removed in vacuo to give a mixture of 1-butyryloxy-5,5-di-methyl-4-phenyl cyclohex-1-ene-3-one and 1-butyryloxy-5,5-dimethyl-6-phenyl cyclohex-1-ene-3-one. Toluene (100 ml) was added, followed by 4-(N-dimethylamino) pyridine (1 g) and the mixture was refluxed for 3 hours. Evaporation of the toluene in vacuo gave a red oil which was purified on a silica gel column using 5% (v/v) diethyl ethermethylene chloride as eluant to give the title compound (6 g) as a pale yellow oil.

Provenance & Evidence