Hydrochloric Acid → HCID 19775798, compound

Participants

Reaction Steps

3-Cyclopentenecarboxylic acid (7.5 g, 66.9 mmole) in dry tetrahydrofuran (15 ml) was added dropwise under nitrogen to a stirred solution of lithium diisopropylamide prepared from diisopropylamine (19.7 ml, 0.14 mole) and 2.5M n-butyl lithium in hexane (56.2 ml, 0.14 mole) in dry tetrahydrofuran (150 ml) at -60° C. The resulting suspension was allowed to warm to room temperature and then stirred for a further hour, by which time a clear solution was obtained. Iodopropane (7.18 ml, 73.6 mmole) was added dropwise at -60° C., and the mixture was once again allowed to warm to room temperature and then stirred overnight. The solution was cooled to 15° C., water (10 ml) was added followed by 2N hydrochloric acid to pH 3. The organic layer was separated and the aqueous phased extracted twice with methylene chloride. The combined organic extracts were washed with saturated salt solution, dried (MgSO4) and evaporated under vacuum to give a crude product which was chromatographed on silica gel (200 g), eluting with a mixture of ethyl acetate and hexane to give 1-propyl-3-cyclopentene-carboxylic acid (7.96 g, 77%) as a hygroscopic solid.

Provenance & Evidence