반응 #80477

반응 방정식

Potassium t-butoxide

isobutyraldehyde

diethyl succinate

→

2-carboethoxycarbonyl-4-methyl pentanoic acid

용매

t-butanol

t-butanol

반응 조건

후처리

1. 1
   온도under reflux, for 2 h
2. 2
   기타The solvent was removed from the reaction mixture by evaporation under reduced pressure
3. 3
   추출The product was extracted with ethyl ether, Et2O (3×200 ml)
4. 4
   세척The ether solution was washed with water (3×200 ml)
5. 5
   추출and the product was extracted with 10% Na2CO3 (4×200 ml)
6. 6
   기타the product was isolated by extraction with Et2O (4×150 ml)
7. 7
   세척The ether layer was washed with water
8. 8
   건조dried over sodium sulfate
9. 9
   기타evaporated
10. 10
    workup.DISSOLUTIONThe remaining oil was dissolved in ethanol (300 ml) and hydrogenated in the presence of 10% palladium on charcoal (3.0 g)
11. 11
    여과The resultant mixture was filtered through Celite
12. 12
    기타the solvent was evaporated

실험 절차

Potassium t-butoxide, 24.7 g (0.35M), was dissolved in 200 ml of refluxing t-butanol. A mixture of isobutyraldehyde, 18.2 ml (0.20M) and diethyl succinate 41.55 ml (0.25M) was added to the t-butanol solution over 30 min. The reaction mixture was stirred under reflux, for 2 h. The solvent was removed from the reaction mixture by evaporation under reduced pressure and acidified with 2N HCl. The product was extracted with ethyl ether, Et2O (3×200 ml). The ether solution was washed with water (3×200 ml); and the product was extracted with 10% Na2CO3 (4×200 ml). The solution was acidified with conc. HCl solution and the product was isolated by extraction with Et2O (4×150 ml). The ether layer was washed with water, dried over sodium sulfate, and evaporated. The remaining oil was dissolved in ethanol (300 ml) and hydrogenated in the presence of 10% palladium on charcoal (3.0 g). The resultant mixture was filtered through Celite and the solvent was evaporated to yield 38.04 g 2-carboethoxycarbonyl-4-methyl pentanoic acid as a mixture of isomers in the form of an oil. The isolated monoethyl ester was further purified on silica gel by flash chromatography using as eluent mixture ethyl acetate: hexane:acetic acid (1:10:0.05, v/v).

출처