反应详情

To a solution of ethyl 4-(3-chloro-4-fluorophenyl)cyclohex-3-ene-1-carboxylate (270 mg, 0.955-mmoL) in EtOAc (15 mL) was added 10% Pd/C (45 mg). The reaction was put under an atmosphere of H2 (balloon) and stirred vigorously at room temperature. After 30 min, the catalyst was removed by filtration, and the filtrate was concentrated to afford a mixture of cis and trans products. The desired trans isomer was separated by flash chromatography on silica gel (0 to 10% EtOAc/hexanes) to afford ethyl trans-4-(3-chloro-4-fluorophenyl)cyclohexanecarboxylate. Rf=0.25 (5% EtOAc/hexanes). 1H NMR (500 MHz, CDCl3): δ 7.21 (d, J=7.3 Hz, 1H), 7.02-7.06 (m, 2H), 4-14 (q, J=7.1 Hz, 2H), 2.48 (m, 1H), 2.32 (m, 1H), 2.08-2.12 (m, 2H), 1.91-1.98 (m, 2H), 1.53-1.67 (m, 2H), 1.37-1.46 (m, 2H), 1.27 (t, J=7.1 Hz, 3H).

1. customthe catalyst was removed by filtration
2. concentrationthe filtrate was concentrated
3. customto afford
4. additiona mixture of cis and trans products
5. customThe desired trans isomer was separated by flash chromatography on silica gel (0 to 10% EtOAc/hexanes)