Water → Tert-butyl 4-(3,3-dibromoallyl)piperidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

Carbon tetrabromide (46.7 g, 141 mmol) was dissolved in 200 mL dichloromethane. The solution was cooled in an ice-water bath and triphenylphosphine (73.9 g, 282 mmol) in 200 mL dichloromethane was introduced via an addition funnel over 20 min. The reaction mixture was stirred at 0° C. for 10 min and a solution of tert-butyl 4-(2-oxoethyl)piperidine-1-carboxylate (16 g, 70.4 mmol) in 100 mL dichloromethane was added via an addition funnel. The solution was stirred at 0° C. for 1 hour. Water (250 mL) was added and aqueous layer was extracted 3 times with 100 mL dichloromethane. The combined organic layer was washed with brine, dried over sodium sulfate, filtered and concentrated. 300 mL ether was added to the residue, and the resulting suspension was filtered. The solid was washed 3 times with 150 mL ether. The combined filtrate was concentrated and passed through a plug of silica gel, washed thoroughly with 10% acetone/hexanes to afford yellow oil which was used without further purification.

Provenance & Evidence