反应详情

1,1,1-Tribromo-4-methyl-3-penten-2-ol (6.72 g, 0.02 mole) and anhydrous sodium acetate (0.008 g) were melted together at 90°. The temperature of the mixture was then reduced to 80°, and diketene (about 2.6 ml, 0.022 mole) was added dropwise over a 10 minute period. The resulting mixture was heated at 80° for three additional hours. After cooling, the mixture was diluted with ether, and the ethereal solution was washed with 1 N aqueous hydrochloric acid and then ten times with saturated aqueous sodium bicarbonate. The washed mixture was treated with activated charcoal and dried over magnesium sulfate. Evaporation of the ether afforded 3-methyl-1-tribromomethyl-2-butenyl acetoacetate (8.34 g, 99% yield) as an oily residue.

1. customwere melted together at 90°
2. customwas then reduced to 80°
3. temperatureThe resulting mixture was heated at 80° for three additional hours
4. temperatureAfter cooling
5. washthe ethereal solution was washed with 1 N aqueous hydrochloric acid
6. additionThe washed mixture was treated with activated charcoal
7. dry with materialdried over magnesium sulfate
8. customEvaporation of the ether