反应详情

A mixture of 5,7-dimethoxyspiro[2H-1-benzopyran-2,1'-cyclohexan]-4(3H)-one [H.F.Birch, A.Robertson, and T.S.Subramanjam, J.Chem.Soc., 1832 (1936)] (1.3 g, 6.25 mmol) and 48% hydrobromic acid (50 ml) is heated to reflux for one hour. After cooling, the reaction mixture is concentrated under reduced pressure. The concentrate is extracted with diethyl ether and the extract is washed with water, dried, and concentrated. The residue is placed on a silica gel column and eluted with diethyl ether. The eluate is treated with ether to yield the title compound as a crystalline solid (0.65 g, 58%).

1. temperatureis heated
2. temperatureto reflux for one hour
3. temperatureAfter cooling
4. concentrationthe reaction mixture is concentrated under reduced pressure
5. extractionThe concentrate is extracted with diethyl ether
6. washthe extract is washed with water
7. customdried
8. concentrationconcentrated
9. washeluted with diethyl ether
10. additionThe eluate is treated with ether