反応手順
A mixture of 164a (200 mg, 0.30 mmol) and NaBH4 (36 mg, 0.90 mmol) in methanol (30 mL) was stirred at 30° C. for 2 h. The mixture was quenched with water and concentrated under reduced pressure. The residue was extracted with ethyl acetate (3×10 mL). The combined ethyl acetate extract was concentrated under reduced pressure and the residue was purified by reverse-phase prep-HPLC to afford 164 (140 mg, 72%) as light green solid. MS-ESI: [M+H]+ 679.3. 1H NMR (500 MHz, CDCl3) δ 8.63 (d, J=2.5 Hz, 1H), 8.49 (d, J=5.0 Hz, 1H), 7.93 (d, J=2.5 Hz, 1H), 7.83 (s, 1H), 7.82 (s, 1H), 7.37 (d, J=5.0 Hz, 1H), 7.27 (s, 1H), 6.85 (s, 1H), 6.82 (d, J=9.0 Hz, 1H), 5.06 (s, 1H), 4.71-4.61 (m, 5H), 4.52-4.50 (m, 1H), 4.34-4.32 (m, 1H), 4.16 (d, J=4.5 Hz, 2H), 3.87-3.85 (m, 1H), 3.72 (s, 3H), 3.55-3.50 (m, 1H), 3.33-3.30 (m, 1H), 3.12 (t, J=5.0 Hz, 2H), 2.58-2.55 (m, 3H), 2.52 (s, 2H), 2.44 (d, J=3.5 Hz, 2H), 2.35 (t, J=5.5 Hz, 1H), 1.68-1.64 (m, 1H), 1.42-1.37 (m, 1H), 1.28 (s, 6H), 0.82 (t, J=7.5 Hz, 3H).
