反应详情

A solution of 4-ethoxycarbonylmethoxybutyric acid ethyl ester (90%, 15.0 g, 61.9 mmol) in toluene (300 mL) was stirred at room temperature and treated over 5 min with a solution of potassium tert-butoxide in tetrahydrofuran (1.0 M, 74.2 mL, 74.2 mmol). The mixture was stirred at room temperature for 24 h , then was poured into 1 N hydrochloric acid. The phases were separated, and the aqueous phase was extracted with ether. The combined organic phases were dried (Na2SO4), filtered and concentrated in vacuo. The residue was purified by flash column chromatography (5% ethyl acetate/hexanes) to provide the product as a pale yellow liquid (5.06 g, 48%). 1H NMR (300 mHz, CDCl3) δ11.85 (s, 1H), 4.24 (q, J=7.3 Hz, 2H), 4.14 (t, J=1.7 Hz, 2H), 3.79 (t, J=5.5 Hz, 2H), 2.35 (tt, J=5.5, 1.7 Hz, 2H), 1.32 (t, J=7.3 Hz, 3H).

1. customThe phases were separated
2. extractionthe aqueous phase was extracted with ether
3. dry with materialThe combined organic phases were dried (Na2SO4)
4. filtrationfiltered
5. concentrationconcentrated in vacuo
6. customThe residue was purified by flash column chromatography (5% ethyl acetate/hexanes)