反应详情

To a suspension of sodium hydride (5.2 g, 130 mmol, 60% in mineral oil) in tetrahydrofuran (100 mL) at 0° C. was added dropwise a solution of heptane-3,5-dione (16.6 g, 130 mmol) in tetrahydrofuran (30 mL). After 15 minutes, bromo-acetic acid ethyl ester (14.4 mL, 130 mmol) was added and the reaction mixture was stirred for 16 h at room temperature. The reaction mixture was poured into an aqueous ammonium chloride solution and extracted several times with ethyl acetate. The combined ethyl acetate layers were washed with water and a saturated aqueous solution of sodium chloride, dried over sodium sulfate, and concentrated under reduced pressure. The crude product was purified by silica gel column chromatography (0-30% ethyl acetate in heptane) to obtain 4-oxo-3-propionyl-hexanoic acid ethyl ester (19 g, 68%) as yellow oil.

1. extractionextracted several times with ethyl acetate
2. washThe combined ethyl acetate layers were washed with water
3. dry with materiala saturated aqueous solution of sodium chloride, dried over sodium sulfate
4. concentrationconcentrated under reduced pressure
5. customThe crude product was purified by silica gel column chromatography (0-30% ethyl acetate in heptane)