反应详情

11.2 g (200 mmol) of potassium hydroxide in 75 ml of water are added at 0° dropwise to a suspension of 11.6 g (100 mmol) of 2-oxo-n-valeric acid and 12.6 g (100 mmol) of 2-acetylthiophene in 75 ml of ethanol and the suspension is held at 0° for 48 hours. After evaporation of the ethanol the residue is made acidic with 25% hydrochloric acid and extracted three times with ethyl acetate. The combined ethyl acetate extracts are dried, filtered and evaporated. After chromatography on silica gel using a 5:1 mixture of methylene chloride and methanol as the eluent and crystallisation from ether there are obtained 10.0 g (41%) of rac-α-hydroxy-α-propyl-γ-oxo-2-thiophenebutyric acid as a colorless powder, melting point 128°-131°, MS: 197 (M-COOH)+.

1. customAfter evaporation of the ethanol the residue
2. extractionextracted three times with ethyl acetate
3. dry with materialThe combined ethyl acetate extracts are dried
4. filtrationfiltered
5. customevaporated
6. additionAfter chromatography on silica gel using a 5:1 mixture of methylene chloride and methanol
7. customas the eluent and crystallisation from ether