Reaction Steps
A mixture of 149a (97 mg, 0.15 mmol), NaBH4 (17 mg, 0.45), and methanol (10 mL) was stirred at 25° C. for 1 h. The reaction mixture was then quenched with water (10 mL) and concentrated under reduced pressure. The residue was extracted with dichloromethane (2×10 mL). The combined dichloromethane extract was concentrated under reduced pressure and the residue was purified with reverse-phase prep-HPLC to afford 149 (62 mg, 63%). MS-ESI: [M+H]+ 651.3. 1H NMR (500 MHz, DMSO-d6) δ 8.63 (s, 1H), 8.46 (d, J=5.0 Hz, 1H), 8.43 (s, 1H), 7.83 (d, J=3.0 Hz, 1H), 7.48 (d, J=2.0 Hz, 1H), 7.38-7.36 (m, 1H), 7.31 (J=5.0 Hz, 1H), 7.25-7.23 (m, 1H), 6.04 (s, 1H), 4.57-4.55 (m, 2H), 4.48-4.46 (m, 1H), 4.42-4.38 (m, 2H), 4.35-4.33 (m, 1H), 4.15-4.12 (m, 1H), 3.96-3.94 (m, 1H), 3.82-3.78 (m, 2H), 3.69-3.67 (m, 1H), 3.59 (s, 3H), 3.41-3.38 (m, 2H), 3.18-3.15 (m, 2H), 3.00-2.95 (m, 3H), 2.73-2.71 (m, 2H), 2.30-2.28 (m, 2H), 2.20-2.16 (m, 1H), 1.93-1.89 (m, 3H), 1.77-1.75 (m, 1H), 0.93 (d, J=6.5 Hz, 3H).
