Reaction Steps
To a solution of 19 (400 mg, 0.82 mmol) in THF (20 mL) at 0° C. was added LiAlH4 (48 mg, 1.2 mmol) in several portions. The reaction mixture was allowed to stir at 0° C. for an additional 10 min then quenched with H2O (25 μL). The solvent was removed by rotary evaporation, and the crude product was purified by flash column chromatography (EtOAc:hexanes, 2:1-4:1) to give 20 (280 mg, 0.66 mmol, 80%) as a colorless oil: 1H NMR (500 MHz, CDCl3) δ 2.12 (s, 6H), 2.39 (s, 3H), 2.64-2.67 (dd, J=2.0, 12.0 Hz, 1H), 2.70-2.90 (m, 2H), 2.98-3.03 (dd, J=5.5, 12.5, Hz, 1H), 3.40-3.44 (dd, J=3.0, 11.5 Hz, 1H), 3.56-3.58 (dd, J=3.0, 6.0 Hz, 1H), 3.65-3.69 (dd, J=7.5, 11.5 Hz, 1H), 3.76-3.79 (d, J=13.0 Hz, 1H), 3.83-3.86 (d, J=13.0 Hz, 1H), 3.90-3.94 (dd, J=5.0, 12.5 Hz, 1H), 3.99-4.03 (dd, J=5.5, 12.5 Hz, 1H), 5.15-5.17 (dd, J=1.0, 10.5 Hz, 1H), 5.23-5.27 (dd, J=1.0, 18.5 Hz, 1H), 5.80-5.96 (m, 3H), 6.86 (s, 1H), 6.99 (s, 1H), 7.24-7.40 (m, 5H); 13C NMR (125 MHz, CDCl3) δ 13.5, 21.2, 37.7, 46.4, 49.5, 54.0, 60.8, 70.9, 79.4, 98.9, 106.9, 117.2, 120.4, 123.7, 127.6, 128.6, 128.7, 128.9, 135.0, 139.2, 149.8, 151.8, 160.6; LCQ-MS (M+H+) calcd for C27H36N3O2 434. found 434; LC-TOF-MS (M+H+) calcd for C27H36N3O2 434.28075. found 434.28071.
