(1R,2S,5R)-5-methyl-2-(propan-2-yl)cyclohexyl(2S)-cyclopentyl(4-methylphenyl)ethanoate → (2S)-Cyclopentyl-(4-methylphenyl)acetic acid

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Reaction Steps

50.0 g (0.140 mol) of (1R,2S,5R)-5-methyl-2-(propan-2-yl)cyclohexyl(2S)-cyclopentyl(4-methylphenyl)ethanoate were stirred under reflux for 16 h in 500 ml of trifluoroacetic acid. The trifluoroacetic acid was then removed on a rotary evaporator and the residue was taken up in 500 ml each of water and ethyl acetate. After extraction, the organic phase was washed with saturated sodium chloride solution, dried over sodium sulfate and concentrated. The residue was taken up in 1.5 liters of water, adjusted to pH 10 with aqueous sodium hydroxide solution and washed twice with in each case 300 ml of tert-butyl methyl ether. The aqueous phase was then adjusted to pH 4 using concentrated hydrochloric acid and extracted twice with in each case 300 ml of ethyl acetate. The combined ethyl acetate extracts were dried over sodium sulfate, filtered and concentrated on a rotary evaporator. This gave 27.4 g (89% of theory) of the title compound.

Provenance & Evidence