Ethyl 4-oxocyclohexanecarboxylate → Ethyl 4-methylidenecyclohexane-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of (methyl)triphenylphosphonium bromide (5.18 g, 14.51 mmol) in THF (50 mL) at 0° C. was added n-butyllithium (9.07 mL, 14.51 mmol). The reaction mixture was stirred at 0° C. for 30 min. Ethyl 4-oxocyclohexanecarboxylate (1.9 g, 11.16 mmol) in THF (8 mL) was then added at 0° C. and the reaction was warmed to rt and stirred for 2 h. The reaction was quenched with sat′d aq. NH4Cl and diluted with EtOAc. The organic layer was washed with water and brine, dried over MgSO4, filtered, and concentrated in vacuo. The residue was purified by flash chromatography on SiO2 (0 to 50% EtOAc:hexanes) to afford the title compound (1.58 g, 84% yield) as a colorless oil. 1H NMR (500 MHz, CDCl3) δ 4.65 (s, 2H), 4.17-4.11 (m, 2H), 2.44 (tt, J=11.1, 3.8 Hz, 1H), 2.35 (dt, J=13.7, 4.0 Hz, 2H), 2.11-1.96 (m, 4H), 1.64-1.54 (m, 2H), 1.28-1.23 (m, 3H).

Provenance & Evidence