反应详情

温度

-78 °C

A solution of methyl 2-methyl-3-oxopentanoate (3.24 g) in THF (30 ml) was slowly added to a suspension of NaH (900 mg) in THF (50 ml) at 0° C., and after stirring for 10 minutes, the mixture was cooled to −78° C. and 1.58 M n-BuLi (14.2 ml) was slowly added dropwise. After stirring the reaction solution at −78° C. for 30 minutes, a solution of methyl 6-(benzyloxy)benzofuran-2-carboxylate (4.26 g) in THF (15 ml) was slowly added and the mixture was stirred at −78° C. for 4 hours. A saturated ammonium chloride aqueous solution was added to the reaction solution, and after bringing it to room temperature, extraction was performed with AcOEt and the organic layer was dried with MgSO4 and then filtered and concentrated. The residue was dissolved in MeOH (30 ml) and THF (10 ml), a 4 N lithium hydroxide aqueous solution (5 ml) and water (50 ml) were added, and after stirring at room temperature for 4 hours, a saturated KHSO4 aqueous solution (30 ml) was slowly added. The deposited yellow precipitate was filtered off and rinsed with AcOEt to obtain 6-(6-(benzyloxy)benzofuran-2-yl)-3,5-dimethyl-4-hydroxy-2H-pyran-2-one.

1. stirringAfter stirring the reaction solution at −78° C. for 30 minutes
2. stirringthe mixture was stirred at −78° C. for 4 hours
3. customto room temperature
4. extractionextraction
5. dry with materialthe organic layer was dried with MgSO4
6. filtrationfiltered
7. concentrationconcentrated
8. dissolutionThe residue was dissolved in MeOH (30 ml)
9. additionTHF (10 ml), a 4 N lithium hydroxide aqueous solution (5 ml) and water (50 ml) were added
10. stirringafter stirring at room temperature for 4 hours
11. additiona saturated KHSO4 aqueous solution (30 ml) was slowly added
12. filtrationThe deposited yellow precipitate was filtered off
13. washrinsed with AcOEt