反应详情

270 ml of stearoyl chloride were added dropwise at a maximum of 150° C. to a solution of 117 g of Meldrum's acid and 131 ml of pyridine in 1.5 l of methylene chloride. After stirring the reaction mixture was washed with 4N hydrochloric acid, the aqueous phase was back-extracted with methylene chloride and the methylene chloride phase was dried and concentrated. The residue was taken up in methanol and stirred under reflux. After cooling the separated crystals were filtered off, dissolved in methylene chloride and chromatographed on silica gel with methylene chloride. There were obtained 175 g of methyl 3-oxoeicosanoate, m.p. 52°-54° C.

1. washwas washed with 4N hydrochloric acid
2. extractionthe aqueous phase was back-extracted with methylene chloride
3. dry with materialthe methylene chloride phase was dried
4. concentrationconcentrated
5. stirringstirred
6. temperatureunder reflux
7. temperatureAfter cooling the separated crystals
8. filtrationwere filtered off
9. dissolutiondissolved in methylene chloride
10. customchromatographed on silica gel with methylene chloride