反应详情

温度

85 °C

The crude dimethyl 7-oxo-6,7,8,9-tetrahydro-5H-benzo[7]annulene-6,8-dicarboxylate was dissolved in 200 mL of ethanol (EtOH) and then 100 mL of 2 N KOH. The resulting mixture was refluxed at 85° C. for 17 h. After cooling to ambient temperature, the volatiles were evaporated. To the residue was added 120 mL of 2N HCl at 0° C., the crude product was extracted by EtOAc (200 mL×2). The combined extracts were washed with brine. After being dried (MgSO4), filtered, and concentrated, the residue was purified by flash column chromatography on silica gel (hexanes/EtOAc 8:1) to afford 6.6 g (57%) of 8,9-dihydro-5H-benzo[7]annulen-7(6H)-one as a white solid: mp 40-41° C.; 1H NMR (300 MHz, CDCl3) δ: 7.21 (m, 4H), 2.94-2.90 (m, 4H), 2.63-2.60 (m, 4H); LC-MS: 161 (M+H)+.

1. temperatureAfter cooling to ambient temperature
2. customthe volatiles were evaporated
3. additionTo the residue was added 120 mL of 2N HCl at 0° C.
4. extractionthe crude product was extracted by EtOAc (200 mL×2)
5. washThe combined extracts were washed with brine
6. dry with materialAfter being dried (MgSO4)
7. filtrationfiltered
8. concentrationconcentrated
9. customthe residue was purified by flash column chromatography on silica gel (hexanes/EtOAc 8:1)