反应详情

Under argon atmosphere, 60% dispersion of sodium hydride (4.6 g, 0.114 mol) in mineral oil was suspended in anhydrous THF (200 ml), and a solution of diethyl methylmalonate (20.0 g, 0.114 mol) in anhydrous THF (20 ml) was dropwise added over one hour with stirring at room temperature. To this reaction mixture, there was added dropwise a solution of 1-bromo-2-pentyne (14.0 g, 0.095 mol) in anhydrous THF (15 ml) at room temperature over 20 minutes. Water (30 ml) was added to the reaction mixture and 3N hydrochloric acid was then added to neutralize. After concentration, the residue was extracted with ethyl acetate (200 ml×2). The organic layer were combined, washed with water (50 ml) and with brine (30 ml), and dried over anhydrous sodium sulfate to concentrate, yielding crude ethyl 2-carboethoxy-2-methyl-4-heptynoate (26.0 g).

1. additionwas then added
2. concentrationAfter concentration
3. extractionthe residue was extracted with ethyl acetate (200 ml×2)
4. washwashed with water (50 ml) and with brine (30 ml)
5. dry with materialdried over anhydrous sodium sulfate
6. concentrationto concentrate