Potassium tert-butoxide → 2-Bromo-4-chloro-1-(2-methylenecyclopentyloxy)benzene

Participants

Reaction Conditions

Reaction Steps

To the mixture of methyl triphenylphosphonium bromide (16.0 g, 44.8 mmol) in anhydrous tetrahydrofuran (125 mL) at 0° C. under nitrogen was added portion wise the potassium tert-butoxide (5.0 g, 44.8 mmol). After stirring at 0° C. for 30 minutes, the mixture of 2-(2-bromo-4-chlorophenoxy)cyclopentanone (516B) (10.8 g, 37.3 mmol) in tetrahydrofuran (40 mL) was added slowly. The resulting mixture was stirred at room temperature under nitrogen for 3 hours. The reaction mixture was quenched with water and extracted with ethyl acetate. The organic phase was washed with water, brine, dried with sodium sulfate and concentrated under reduced pressure. The residue was purified by flash chromatography on silica gel (5-10% EtOAc in hexanes) to provide 2-bromo-4-chloro-1-(2-methylenecyclopentyloxy)benzene (517) (6.2 g, 58.2%) as a colorless oil.

Provenance & Evidence