反应详情

温度

-78 °C

4.75 g of TMEDA was dissolved in 10 ml of THF, and 3.3 g of 3,5-dimethylisoxazole was added. The resulting solution was cooled to −78° C. in a dry ice-acetone bath, and 26 ml of an n-hexane solution of n-butyl lithium (1.6M solution) was dropped into it. They were reacted at the same temperature for 30 minutes, and then, at −78° C., a solution of 1.90 g of 3,4-dihydro-6-methyl-2H-pyran-2-one and 5 ml of DMSO in 10 ml of THF was dropped. The resulting solution was stirred at the same temperature for 2 hours. The dry ice-acetone bath was taken away. After gradually returning to room temperature, the solution was stirred for 15 hours. The reaction solution was poured into dilute hydrochloric acid-ice and extracted with ethyl acetate. The organic layer was washed with water and then with saturated salt water, and dried over anhydrous magnesium sulfate. The solvent was concentrated under reduced pressure. The obtained residue was purified on silica gel column chromatography to give 1.10 g of the title compound as white crystals. Melting point: 104-105° C.

1. customThey were reacted at the same temperature for 30 minutes
2. customAfter gradually returning to room temperature
3. stirringthe solution was stirred for 15 hours
4. extractionextracted with ethyl acetate
5. washThe organic layer was washed with water
6. dry with materialwith saturated salt water, and dried over anhydrous magnesium sulfate
7. concentrationThe solvent was concentrated under reduced pressure
8. customThe obtained residue was purified on silica gel column chromatography