反应详情

温度

-30 °C

To a suspension of sodium hydride (0.16 g) in dry tetrahydrofuran (5 mL) was added dropwise with stirring in an ice bath a solution of isobutyric acid (0.352 g) in dry tetrahydrofuran (5 mMol). After the addition, the mixture was warmed to 50°-55° C. for 15 minutes until all hydrogen evolution had stopped, and was then cooled to -30° C. To the solution was added a solution of lithium diisopropylamide (prepared from diisopropylamine (0.40 g) and n-butyllithium (1.1M solution in hexane) in dry tetrahydrofuran (5 mL) at -20° to -30° C.). After the addition, the solution was warmed to 30°-35° C. for 30 minutes and ethylene oxide (2.0 mL, condensed as a liquid in a dropping funnel fitted with a Dry Ice condenser) was added at 0° C. The mixture was then stirred for 1 hour at room temperature. To the solution was added decanoyl chloride (0.76 g) in 10 mL of dry tetrahydrofuran and the solution was stirred at room temperature for 1 hour and then poured onto ice water. The crude product was extracted with dichloromethane, and the combined extracts were washed with brine, dried (Na2SO4), and evaporated. Chromatography on silica gel (60 g) eluting with 5% MeOH in dichloromethane afforded 0.25 g of 2,2-dimethyl-4-[(1-oxodecyl)oxy]butanoic acid (22.5%). In a larger scale experiment, the crude product was distilled to give the pure decanoate, bp 195°/0.06 mm.

1. additionwas added dropwise
2. additionAfter the addition
3. additionAfter the addition
4. temperaturethe solution was warmed to 30°-35° C. for 30 minutes
5. customfitted with a Dry Ice condenser)
6. additionwas added at 0° C
7. stirringthe solution was stirred at room temperature for 1 hour
8. additionpoured onto ice water
9. extractionThe crude product was extracted with dichloromethane
10. washthe combined extracts were washed with brine
11. dry with materialdried (Na2SO4)
12. customevaporated
13. washChromatography on silica gel (60 g) eluting with 5% MeOH in dichloromethane