反应详情

To a stirred solution of compound (48) (2.0 g, 5.9 mmol) in methanol (25 mL) was added a solution of NaOH (0.8 g, 20 mmol) in 20 mL of water. The reaction mixture was stirred at room temperature for 2 h (monitored by TLC). The reaction mixture was acidified to about pH 5.0 using 0.1 N HCl and then extracted using ethyl acetate (2×50 mL). The combined extracts were washed with brine (40 mL), dried over MgSO4 and concentrated in vacuo. The crude product was purified using flash chromatography on silica gel using hexane/ethyl acetate (1:1) as eluant to provide 1.3 g (75%) of compound (49) as a colorless oil. 1H NMR (400 MHz, CDCl3): δ1.36-1.78 (14H, m); 1.99-2.12 (2H, m); 2.34 (2H, s); 3.23 (2H, d, J=6.4 Hz); 4.09 (1H, m); 5.26 (1H, t, J=6.4 Hz); 5.89 (1H, m). MS (ESI): m/z=298.23 (M−H−).

1. extractionextracted
2. washThe combined extracts were washed with brine (40 mL)
3. dry with materialdried over MgSO4
4. concentrationconcentrated in vacuo
5. customThe crude product was purified