2-Allyl-4-methyl-pent-4-enoic acid ethyl ester → Ethyl 3-methylcyclopent-3-ene-1-carboxylate

Participants

Reaction Steps

To a refluxing stirred solution of the 2-Allyl-4-methyl-pent-4-enoic acid ethyl ester (364 mg, 2.0 mmol) in CH2Cl2 (100 mL, 0.02 M solution) was added drop wise a solution of the tricyclohexylphosphine (1,3-Bis(2,4,6-trimethylphenyl)-4,5-dihydroimidazol-2-ylidene)(benzylidine)ruthenium (IV) dichloride (85 mg, 0.1 mmol) in CH2Cl2 (3.0 mL). After 50 min, the reaction mixture was cooled to room temperature, concentrated and purified on silica gel bond elute using EtOAc/hexane (1:20) as an eluent furnished the 3-Methyl-cyclopent-3-enecarboxylic acid ethyl ester (286 mg, 93% yield) as an oil. 1H NMR (CDCl3, 400 MHz), 5.25 (brs, 1H), 4.17 (q, J=7.1 Hz, 2H), 3.2-3.1 (m, 1H), 2.65-2.46 (m, 4H), 1.74 (s, 3H), 1.28 (t, J=7.1 Hz, 3H).

Provenance & Evidence