反应详情

71 g (0.5 mol) of 3,3-dimethyl-4-pentenoic acid methyl ester were added dropwise to a mixture of 87.5 g (0.5 mol) of p-chlorobenzoyl chloride and 130.3 g (0.5 mol) of tin tetrachloride at 20° C., while cooling with ice. After being left to stand overnight, the reaction mixture had solidified. It was taken up in methylene chloride, the methylene chloride mixture was filtered and the filtrate was extracted by shaking with dilute hydrochloric acid. After drying and stripping off the solvent in vacuo, 111.1 g of crude product (about 83%), which crystallized completely, were obtained. Recrystallization from 120 ml of ethanol gave 3,3-dimethyl-4-(4'-chloro-phenacyl)-γ-butyrolactone of melting point 76°-80° C.

1. temperaturewhile cooling with ice
2. waitAfter being left
3. filtrationthe methylene chloride mixture was filtered
4. extractionthe filtrate was extracted
5. customAfter drying
6. customcrystallized completely
7. customwere obtained
8. customRecrystallization from 120 ml of ethanol