反应详情

A mixture of 5,7-dihydroxyspiro[2H-1-benzopyran-2,1'-cyclohexan]-4(3H)-one (prepared in Preparation 19) (0.248 g, 1.0 mmol), ethyl 2-bromopropionate (0.199 g, 1.1 mmol), anhydrous potassium carbonate (0.207 g, 1.5 mmol), and acetonitrile (3 ml) is stirred at room temperature for 22 hours, and the reaction mixture is concentrated. To the residue is added saturated brine and the mixture is extracted with dichloromethane. The organic layer is separated, dried, and concentrated. Purification by a silica gel column chromatography (eluent: dichloromethane) gives the title compound as an oil (0.284 g, yield 81.6%).

1. concentrationthe reaction mixture is concentrated
2. additionTo the residue is added saturated brine
3. extractionthe mixture is extracted with dichloromethane
4. customThe organic layer is separated
5. customdried
6. concentrationconcentrated
7. customPurification by a silica gel column chromatography (eluent: dichloromethane)