反应详情

Under nitrogen atmosphere, 0.37 g of metallic potassium was added into 40 ml of absolute ethanol, to prepare potassium ethoxide. The prepared potassium ethoxide was added dropwise into a 100 ml flask containing 1.48 g of ethyl 3-methyl-2-cyanobutyrate. The reaction mixture was stirred at room temperature for 1 h, and then evaporated off the solvent to afford white solids. The white solids were dissolved in 25 ml of tetrahydrofuran, and then the resultant solution was slowly added dropwise into a solution of 2.2 g of ethyl 2-bromoisopentanoate in 30 ml of tetrahydrofuran, and the reaction mixture was heated to reflux for 9 h. Then the solvent was evaporated, to afford a mixture of yellow sticky liquid and pale yellow solids. To this mixture were added with 75 ml of diethyl ether and 20 ml of water, and an organic phase was separated. The organic phase was washed with 20 ml of 10% aqueous NaHCO3 solution twice, and then with water until the organic phase was neutral. The organic phase was dried over anhydrous magnesium sulfate over night, filtered, and evaporated off the solvent, to afford a yellow clear liquid. The yellow clear liquid was separated on a silica chromatographic column (eluent: petroleum ether and chloroform), to afford a pale yellow clear liquid.

1. customevaporated off the solvent
2. customto afford white solids
3. temperaturethe reaction mixture was heated
4. temperatureto reflux for 9 h
5. customThen the solvent was evaporated
6. customto afford
7. additiona mixture of yellow sticky liquid and pale yellow solids
8. customan organic phase was separated
9. washThe organic phase was washed with 20 ml of 10% aqueous NaHCO3 solution twice
10. dry with materialThe organic phase was dried over anhydrous magnesium sulfate over night
11. filtrationfiltered
12. customevaporated off the solvent
13. customto afford a yellow clear liquid
14. customThe yellow clear liquid was separated on a silica chromatographic column (eluent: petroleum ether and chloroform)
15. customto afford a pale yellow clear liquid