反应详情

To a mixture of 1-(2,2,5-trimethyl-1,3-dioxane5-yl)ethanone (0.76 g, 4.4 mmol) and THF (7.6 mL) was added sodium hydride (0.16 g, 6.6 mmol) under nitrogen atmosphere, and the resulting mixture was stirred at room temperature for 0.5 hour. To the resulting reaction mixture was added dimethyl oxalate (0.78 g, 6.6 mmol) and the mixture was heated at reflux for 2 hours. After the reaction was completed, saturated ammonium chloride aqueous solution was added to mixture and the resulting mixture was extracted with ethyl acetate. The extract was washed with brine, dried over anhydrous sodium sulphate, and concentrated in vacuo. The resulting residue was purified on a silica gel column chromatography (ethyl acetate/n-hexane) to give methyl 2,4-dioxo-4-(2,2,5-trimethyl-1,3-dioxane5-yl)butanoate (1.0 g, yield: 88%) as colorless oil.

1. customTo the resulting reaction mixture
2. temperaturethe mixture was heated
3. temperatureat reflux for 2 hours
4. extractionthe resulting mixture was extracted with ethyl acetate
5. washThe extract was washed with brine
6. dry with materialdried over anhydrous sodium sulphate
7. concentrationconcentrated in vacuo
8. customThe resulting residue was purified on a silica gel column chromatography (ethyl acetate/n-hexane)