Ethylene → 2,4,4-trimethylcyclohex-2-en-1-one

Participants

Reaction Conditions

Reaction Steps

Aluminium chloride (60.6 g, 0.454 moles) Was added to 1,2-dichloroethane (200 ml) and the mixture cooled to about 0° C. Propanoyl chloride (40 g, 0.432 moles) was then added over a period of 20 minutes and the temperature of the reaction mixture allowed to rise to 20° C. to give a clear pale orange solution. This solution was stirred for 30 minutes and ethene (12 g, 0.432 moles) was then bubbled into the solution over a period of about 11/2 hours. The mixture was then quenched in a mixture of concentrated hydrochloric acid (65 ml) and ice (330 ml) and the organic phase separated and backwashed with water (2×50 ml). 2-Methylpropanal (22 g, 0.3 moles) and para-toluenesulphonic acid (1.65 g, 8.64 mmoles) were then added and the mixture refluxed with azeotropic water removal until no more water separated. The organic phase was then washed with 10% (w/v) sodium hydroxide (200 ml) and the solvent removed. Distillation gave 30 g 2,4,4-trimethylcyclohex-2-en-1-one, b.pt. 40° C. at 0.3 mm Hg. (Yield: 72%)

Provenance & Evidence