反应详情

21B (1.47 g, 3.84 mmol) was dissolved in MeOH (15 mL) at 0° C. NaBH4 (0.175 g, 4.61 mmol) was added. The reaction mixture was stirred rt for 1 h. quenched with water, extracted with EtOAc (2×). The extract was dried over sodium sulfate and concentrated. The crude was purified by prep HPLC. To give 21C (830 mg, 2.159 mmol, 56.2% yield). MS (ESI) m/z: 385.4 (M+H)+. 1H NMR (400 MHz, chloroform-d) δ ppm 7.95 (dd, J=11.86, 2.20 Hz, 1H) 7.88 (s, 1H) 4.70 (d, J=11.86 Hz, 1H) 4.51 (s, 3H) 4.35 (d, J=13.62 Hz, 1H) 4.20 (t, J=7.91 Hz, 1H) 3.21 (t, J=7.47 Hz, 1H) 2.75 (s, 3H) 1.45 (s, 9H) 0.90 (dd, J=8.13, 4.17 Hz, 1H) 0.49-0.61 (m, 2H) 0.41 (td, J=9.23, 4.83 Hz, 1H) 0.22-0.29 (m, 1H).

1. customquenched with water
2. extractionextracted with EtOAc (2×)
3. dry with materialThe extract was dried over sodium sulfate
4. concentrationconcentrated
5. customThe crude was purified by prep HPLC