反应详情

To a mixture of but-3-enoic acid methyl ester (1.00 g, 10 mmol) and zinc-copper couple (1.97 g) in 1,2-dimethoxyethane (4.89 ml) and diethyl ether (37 ml), trichloroacetyl chloride (2.98 ml, 26.7 mmol) is added at room temperature under nitrogen. The mixture is stirred at room temperature for 3 days. The mixture is filtrated and washed with diethyl ether. The filtrate is concentrated under reduced pressure, and the obtained residue is purified by silica gel column chromatography to give (2,2-dichloro-3-oxo-cyclobutyl)-acetic acid methyl ester (2.93 g, quant.); TLC (hexane/AcOEt, 3:1) Rf 0.35, 1H NMR (400 MHz, chloroform-d) δ ppm 2.68-2.74 (m, 1H), 2.94-3.00 (m, 1H), 3.06-3.13 (m, 1H), 3.33-3.41 (m, 1H), 3.51-3.57 (m, 1H), 3.75 (s, 3H).

1. additionis added at room temperature under nitrogen
2. filtrationThe mixture is filtrated
3. washwashed with diethyl ether
4. concentrationThe filtrate is concentrated under reduced pressure
5. customthe obtained residue is purified by silica gel column chromatography