反应详情

To a solution of ethylacetoacetate (11.0 g, 85 mmol) in THF (20 ml) at 0° C. under argon atmosphere was added isopropylmagnesium chloride (42 ml, 2 M in THF, 85 mmol) dropwise. The reaction was stirred for 0.5 h. This solution was then transferred by cannula to a solution of cyclopropylcarbonylchloride (8.8 g, 85 mmol) and imidazole (0.3 g, 4 mmol) in THP (30 ml), also under argon at 0° C. The reaction was stirred for 2 h at 0° C. and 1 h at room temperature before the reaction was quenched by addition of 10% citric acid solution. The reaction was then extracted with EtOAc, dried (Na2SO4) and concentrated. Purification by flash column chromatography (EtOAc:n-heptane 5:95) afforded the title compound (11.9 g, 71%) as a colorless oil. 1H NMR (300 MHz, CDCl3) δ 0.99-1.02 (2H, m), 1.22-1.24 (2H, m), 1.35 (3H, t, J=6 Hz), 2.32 (3H, s), 2.41-2.51 (1H, m), 4.30 (2H, q, J=6 Hz), 17.95 (1H, s).

1. stirringThe reaction was stirred for 2 h at 0° C. and 1 h at room temperature before the reaction
2. customwas quenched by addition of 10% citric acid solution
3. extractionThe reaction was then extracted with EtOAc
4. dry with materialdried (Na2SO4)
5. concentrationconcentrated
6. customPurification by flash column chromatography (EtOAc:n-heptane 5:95)