反应详情

To a solution of 9 (0.46 g, 2.0 mmol) in acetone (20 mL) was added H2SO4 (5%, 2 mL) and the reaction was heated to reflux for 1.6 h. After the reaction was cooled to room temperature, most of the solvent was then removed in vacuo. A solution of NaHCO3 (sat. 40 mL) was added and the organics were extracted with EtOAc (3×40 mL) and the combined organic layers were washed with brine (30 mL) and dried over Na2SO4. The crude product obtained by removal of the solvent in vacuo was purified by flash column chromatography on silica (Rf=0.10, EtOAc/Hexane, 10:90, v:v) to give the product (0.20 g, 50%) as oil; 1H NMR (CDCl3, 500 MHz): δ 9.76 (s, 1 H), 6.88-6.82 (m, 2 H), 6.74 (dd, J=4.6, 8.6 Hz, 1 H), 3.79 (s, 3 H), 2.61 (t, J=7.3 Hz, 2 H), 2.45 (m, 2 H), 1.69-1.60 (m, 4 H).

1. temperaturethe reaction was heated
2. temperatureto reflux for 1.6 h
3. customwas then removed in vacuo
4. additionA solution of NaHCO3 (sat. 40 mL) was added
5. extractionthe organics were extracted with EtOAc (3×40 mL)
6. washthe combined organic layers were washed with brine (30 mL)
7. dry with materialdried over Na2SO4
8. customThe crude product obtained by removal of the solvent in vacuo
9. customwas purified by flash column chromatography on silica (Rf=0.10, EtOAc/Hexane, 10:90, v:v)