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