反应详情

To a stirred solution of compound 89 (1.30 g, 0.58 mmol) in acetic acid (34 mL), protected against light exposure, was added dropwise during 24 h, at room temperature, zinc dust (1.63 g, 24.9 mmol). The mixture was then cooled to 0° C. before addition of a 3 N aqueous sodium hydroxide solution (130 mL). After return back to room temperature, the mixture was extracted with dichloromethane (3×200 mL). The organic layers were combined, dried on magnesium sulfate, filtered and evaporated under reduce pressure. The residue was chromatographed (Al2O3, CH2Cl2/EtOH, 97/3, v/v) to give compound 90 (778 mg, 3.68 mmol) as a yellow oil. Yield 64%; Rf (Al2O3, CH2Cl2/EtOH, 97/3, v/v) 0.54; IR (CCl4) ν 1264, 1413, 1608, 2972 cm−1; 1H NMR (400 MHz, CDCl3) δ 0.98 (t, 6H, J=7.3 Hz), 2.44 (q, 6H, J=7.1 Hz), 3.55 (s, 2H), 3.81 (s, 2H), 7.05 (d, 1H, J=4.9 Hz), 7.95 (d, 1H, J=4.9 Hz).

1. additionwas added dropwise during 24 h, at room temperature
2. extractionAfter return back to room temperature, the mixture was extracted with dichloromethane (3×200 mL)
3. customdried on magnesium sulfate
4. filtrationfiltered
5. customevaporated
6. customThe residue was chromatographed (Al2O3, CH2Cl2/EtOH, 97/3