反应详情

Diethyl malonate (8.0 mL, 0.052 mol) was added dropwise to a solution of sodium hydride (60% w/w in oil, 4.2 g, 0.11 mol) in anhydrous tetrahydrofuran (130 mL) that cooled with ice bath. The mixture was refluxed for 7 min. The reaction mixture was cooled with ice bath, chloroacetyl chloride (4.2 mL, 0.052 mol) was added dropwise to the reaction mixture and stirred for 1 h then stirred at 45° C. for 1 h. Cooled to ambient temperature, the reaction mixture was diluted with water, and extracted with chloroform for 4 times. The organic layer was dried over magnesium sulfate and concentrated. The residue was purified by chromatography on silica gel(chloroform/methanol) to afford ethyl 2-ethoxy-4-oxo-4,5-dihydrofuran-3-carboxylate as solid (5.0 g, y. 48%).

1. temperaturecooled with ice bath
2. temperatureThe mixture was refluxed for 7 min
3. temperatureThe reaction mixture was cooled with ice bath
4. stirringthen stirred at 45° C. for 1 h
5. extractionextracted with chloroform for 4 times
6. dry with materialThe organic layer was dried over magnesium sulfate
7. concentrationconcentrated
8. customThe residue was purified by chromatography on silica gel(chloroform/methanol)