反应详情

To a solution of Meldrum's acid (22.0 g) and pyridine (25.0 ml) in dichloromethane (100 ml) was added dropwise pent-4-enoyl chloride (18.5 ml) under ice-cooling. The reaction mixture was stirred at room temperature for 10 hr, and washed with water and 1M hydrochloric acid. The organic layer was dried over anhydrous magnesium sulfate, and the solvent was evaporated. The residue was dissolved in methanol (150 ml), and the mixture was stirred with heating under reflux for 8 hr. After cooling the reaction mixture to room temperature, the solvent was evaporated under reduced pressure. The residue was purified by silica gel column (hexane/ethyl acetate=10/1 to hexane/ethyl acetate=5/1) to give the title compound as a pale-yellow liquid (4.57 g, 40%).

1. temperaturecooling
2. washwashed with water and 1M hydrochloric acid
3. dry with materialThe organic layer was dried over anhydrous magnesium sulfate
4. customthe solvent was evaporated
5. dissolutionThe residue was dissolved in methanol (150 ml)
6. stirringthe mixture was stirred
7. temperaturewith heating
8. temperatureunder reflux for 8 hr
9. temperatureAfter cooling the reaction mixture to room temperature
10. customthe solvent was evaporated under reduced pressure
11. customThe residue was purified by silica gel column (hexane/ethyl acetate=10/1 to hexane/ethyl acetate=5/1)