反应详情

温度

60 °C

36.1 g of sodium (cut into small pieces) is introduced into a three-necked flask equipped with reflux condenser, dropping funnel, and agitator. To this is added 800 ml of absolute ethanol dropwise so quickly that the solution keeps boiling vigorously. To the hot alcoholate solution is added dropwise 269.6 g of freshly distilled methylmalonic acid diethyl ester, the mixture is stirred for 0.5 hour at 60° C. and then--likewise in droplet form--241.7 g of dimethylallyl bromide is added thereto. After one hour of agitation with heating, the thus-precipitated sodium bromide is removed by filtering, the precipitate is washed, and the filtrate is concentrated. The residue is taken up in ether, washed neutral with saturated sodium chloride solution, dried over magnesium sulfate, and concentrated with the use of a forced-circulation evaporator. The evaporation residue is fractionated on an oil pump. *Yield: 266 g of the title compound, bp7 97°-112° C.

1. customequipped
2. temperaturewith reflux condenser
3. temperatureAfter one hour of agitation with heating
4. customthe thus-precipitated sodium bromide is removed
5. filtrationby filtering
6. washthe precipitate is washed
7. concentrationthe filtrate is concentrated
8. washwashed neutral with saturated sodium chloride solution
9. dry with materialdried over magnesium sulfate
10. concentrationconcentrated with the use of a forced-circulation evaporator
11. custom*Yield: 266 g of the title compound, bp7 97°-112° C.