[CH2:1]1[CH:13]2[CH:5]([C:6]3[CH2:7][CH2:8][CH2:9][CH2:10][C:11]=3[C:12]2=O)[CH2:4][CH2:3][CH2:2]1.[CH3:15][Mg]Br.Cl>O1CCCC1>[CH3:15][C:12]1[C:11]2[CH2:10][CH2:9][CH2:8][CH2:7][C:6]=2[CH:5]2[C:13]=1[CH2:1][CH2:2][CH2:3][CH2:4]2To a solution of 1,2,3,4,4a,5,6,7,8,9a-decahydrofluoren-9-one (90.7 mg, 0.477 mmol) in tetrahydrofuran (5 ml), 0.35 ml (1.05 mmol) of methylmagnesium bromide (3.0 M in Et2O) was added dropwise under nitrogen at −78° C. The resulting cloudy mixture was kept at −78° C. for 3 hours and then allowed to warm to room temperature and stirred for 14 hours. The reaction mixture was acidified with 15% aqueous HCl (5 ml), followed by extraction in Et2O (4×20 ml). All organic layers were combined, washed with water, brine, dried over anhydrous magnesium sulfate, and concentrated in vacuo to give 82.5 mg (92%) of 2,3,4,4a,5,6,7,8-octahydro-9-methyl-1H-fluorene and 1,3,4,5,6,7,8,9a-octahydro-9-methyl-2H-fluorene in the ratio of 3 to 1. 1H-NMR (CDCl3): δ2.6-0.9 (m), 13C. NMR: 155.77, 136.49, 133.51, 111.70, 61.12, 50.29, 42.14, 29.74, 27.41, 25.46, 25.11, 23.38, 22.81.
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