Hydrochloric Acid → Ethyl (+/-)-10,11 dihydro-3-methoxy-5H-dibenzo[a,d]cycloheptene-10-acetate

Participants

Reaction Conditions

Reaction Steps

Ethyl (±)-10,11-dihydro-10-hydroxy-3-methoxy-5H-dibenzo[a,d]cycloheptene-10-acetate (101 g, 0.31 mole) was dissolved in glacial acetic acid (1.8 L) and 12 N HCl (28.5 mL, 0.34 mole) was added. The mixture was placed in a 2.5 L pressure bottle containing 5% Pd/C (20 g, 0.0094 mole), and the resulting mixture was shaken at 35° C. under hydrogen on a Parr hydrogenation apparatus equipped with a jacket heater. After 18 hr, the reaction was cooled to ambient temperature, and the catalyst was removed by filtration. The filtrate was concentrated to give a light yellow oil (85.1 g). This was chromatographed on silica gel (2 kg, step-gradient with 5% to 10% EtOAc/hexanes) to afford the title compound (69.1 g, 72%) as an oil: 1H NMR (250 MHz, CDCl3) δ7.05-7.22 (m, 4 H), 7.01 (d, J=8.2 Hz, 1 H), 6.76 (d, J=2.7 Hz, 1 H), 6.67 (dd, J=8.2, 2.7 Hz, 1 H), 4.30 (d, J=15.0 Hz, 1 H), 4.11-4.25 (m, 2 H), 3.85 (d, J=15.0 Hz, 1 H), 3.70-3.90 (m, 1 H), 3.77 (s, 3 H), 3.31 (dd, J=15.0, 4.1 Hz, 1 H), 2.93 (dd, J=15.0, 9.2 Hz, 1 H), 2.64 (dd, J=15.6, 5.0 Hz, 1 H), 2.52 (dd, J=15.6, 9.3 Hz, 1 H), 1.27 (t, J=7.1 Hz, 3 H).

Provenance & Evidence