1,4-Dichloro-cis-2-butene → HCID 18786343, compound

Participants

Reaction Steps

To a stirred solution of methyl 5-fluoro-3-methoxyphenylacetate (708 mg, 3.6 mmol) in THF (10 ml) was added a 1.0 M solution of potassium t-butoxide in THF (4.0 ml, 4.0 mmol) at -30° C. over 0.25 hr. After stirring for 1 h at the same temperature, a solution of cis-1,4-dichlorobut-2-ene (526 mg, 4.0 mmol) in THF (2 ml) was added dropwise and the reaction mixture was warmed to room temperature over 2 hr period. The reaction mixture was cooled to -30° C., and 1.0 M solution of potassium t-butoxide in THF (4.0 ml, 4.0 mmol) was added and the mixture was stirred overnight at room temperature. The reaction was quenched by the addition of saturated aqueous ammonium chloride solution and extracted with ethyl acetate. The combined extracts were washed with brine, dried with MgSO4 and concentrated in vacuo. Purification by column chromatography (SiO2, 150 g; hexane/ethyl acetate (20/1)) afforded 495 mg (55%) of methyl 1-(5-fluoro-3-methoxyphenyl)cyclopent-3-ene-1-carboxylate as a colorless oil.

Provenance & Evidence