Hydrochloric Acid → Diethyl alpha-(4-methoxyphenacyl)malonate

Participants

Reaction Steps

2.43 g (4.7 mmol) of diethyl α-(3-cyclopentyloxy-4-methoxybenzyl)-α-(4-methoxyphenacyl)malonate [prepared as described in step (ii) above] and 1.26 g (4.7 mmol) of 18-crown-6 were dissolved in 50 ml of benzene, and 4.70 ml (4.7 mmol) of a 1.1M solution of potassium hydroxide in ethanol were added to the resulting solution. The mixture was then stirred for 30 minutes, after which the ethanol in the reaction mixture was removed by distillation under reduced pressure. The remaining reaction solution was heated under reflux for 14 hours and then the reaction mixture was cooled to room temperature. The mixture was then acidified by the addition of 3N aqueous hydrochloric acid, and the resulting mixture was extracted with ethyl acetate. The organic extract was washed with water and dried over anhydrous magnesium sulfate, and then the solvent was removed by distillation under reduced pressure. The residue thus obtained was applied to a silica gel chromatography column and eluted with a 1:4 by volume mixture of ethyl acetate and hexane, to give 1.68 g of the title compound as slightly yellow crystals (yield 81%).

Provenance & Evidence