Pyridine → 3-Benzoylcyclohexene

Participants

Reaction Steps

To a solution of 0.320 g (3.26 mmol) of 2-cyclohexen-1-ol and 0.76 mL (9.40 mmol) of pyridine in 20 mL of CH2Cl2 was added 1.04 mnL (8.96 mmol) of benzoyl chloride via syringe. The reaction mixture was yellow with a white precipitate. The reaction was stirred at room temperature for 17 h. The reaction was quenched by the addition of 50 mL of H2O; the aqueous layer was washed with 4×50 mL of Et2O, and the combined organic layers were dried over MgSO4 and concentrated in vacuo. Purification of the residue by flash chromatography (35 mm, 20 cm, 10% CH2Cl2/hexane) gave 0.635 g (99%) of 3-benzoylcyclohexene as a pale yellow oil: TLC Rf=0.35 (10% CH2Cl2/hexane); IR (CCl4) 3100 (w), 3081 (w), 3038 (w), 2931 (s), 1725 (s), 1550 (s); 1H NMR (CDCl3) δ1.66-2.12 (m, 6H), 5.49 (bs, 1H), 5.79-5.83 (m, 1H), 5.97-6.01 (m, 1H), 7.41 (t, J=7.7, 2H), 7.52 (t, J=7.4, 1H); 8.02-8.04 (m, 2H); 13C NMR (CDCl3) δ19.0, 25.0, 28.4, 68.6, 125.8, 128.3, 129.6, 130.9, 132.7, 132.8, 166.2; LRMS (EI) 203 ((M+1), 3), 202 ((M+), 20), 105 (100); HRMS (EI) calculated for C13H14O2 202.0994 (M+), found 202.1003. The IR, 1H NMR, and 13C NMR matched spectral data reported by Akemark, B. et al., J. Org. Chem. 59:5729-5799 (1994).

Provenance & Evidence