Hydrochloric Acid → 2-(2-(2-Benzyloxyphenyl)ethyl)-2-ethoxycarbonylpentanoic acid

To a solution of diethyl 2-(2-(2-benzyloxyphenyl)ethyl)-2-propylmalonate (10 g) in ethanol (50 ml), a solution of potassium hydroxide (1.9 g) in ethanol (180 ml) was added and the mixture was refluxed under heating for 6.5 hours. Ethanol (45 ml) was added thereto and the mixture was stirred at room temperature for 4 days. The reaction mixture was poured into a dilute hydrochloric acid and extracted with ethyl acetate. The organic layer was washed with a saturated brine and dried over sodium sulfate. The solvent was distilled away under reduced pressure and the residue was subjected to silica gel chromatography (eluent; chloroform-methanol=12:1) to give the subject compound (5.7 g).