反应详情

To a solution of 117 g of Meldrum's acid and 131 ml of pyridine in 1.5 1 of methylene chloride, 270 ml of stearic acid chloride were added dropwise at a maximum temperature of 15° C. After stirring, the reaction mixture was washed with 4N hydrochloric acid, the aqueous phase was extracted with methylene chloride, the methylene chloride phase was dried and concentrated. The residue was taken up in methanol and stirred under reflux. After cooling, the precipitated crystals were filtered off, dissolved in methylene chloride and chromatographed on silica gel with methylene chloride to give 175 g of methyl-3-oxoeicosanoate, m.p. 52°-54° C.

1. washthe reaction mixture was washed with 4N hydrochloric acid
2. extractionthe aqueous phase was extracted with methylene chloride
3. dry with materialthe methylene chloride phase was dried
4. concentrationconcentrated
5. stirringstirred
6. temperatureunder reflux
7. temperatureAfter cooling
8. filtrationthe precipitated crystals were filtered off
9. dissolutiondissolved in methylene chloride
10. customchromatographed on silica gel with methylene chloride