Reaction Steps
To a suspension of 11b-ethyl-9-hydroxy-1,2,5,6,7,11b-hexahydro-dibenzo[a,c]cyclohepten-3-one (17, R2=Ethyl) (11.25 g, 43.9 mmol) and 10% Pd—C (1.40 g, 1.32 mmol) in THF (80 mL) was added pyridine (20 mL) and the mixture was hydrogenated at rt under about 40 psi of hydrogen for about 18 h. The catalyst was removed by filtration through Celite®, and the filtrate was concentrated. The residue was dissolved in DCM (200 mL) and washed with 2N aq. HCl (100 mL), dried over Na2SO4, filtered and concentrated under reduced pressure. The residue was re-dissolved in EtOAc (100 mL) and DCM (100 mL), filtered through a short pad of silica gel, and concentrated until product began to precipitate. Product was collected by filtration, rinsed with EtOAc (10 mL) and dried under reduced pressure to yield (4aS,11bR)-11b-ethyl-9-hydroxy-1,2,4,4a,5,6,7,11b-octahydro-dibenzo[a,c]cyclohepten-3-one; compound with (4aR,11bS)-11b-ethyl-9-hydroxy-1,2,4,4a,5,6,7,11b-octahydro-dibenzo[a,c]cyclohepten-3-one (18, R2=Ethyl) (6.45 g, 57%) as a white solid. LC/MS, method 1, 0.80 min, 319 (M−H)−. 1H NMR (400 MHz, DMSO) 9.14 (s, 1H), 7.11-7.05 (m, 1H), 6.60-6.54 (m, 2H), 2.96-2.86 (m, 1H), 2.65-2.54 (m, 2H), 2.47-2.36 (m, 1H), 2.29-2.20 (m, 1H), 2.20-2.05 (m, 4H), 1.89-1.79 (m, 1H), 1.71-1.51 (m, 3H), 1.49-1.31 (m, 2H), 0.61 (t, J=7.4 Hz, 3H).
