Allyl bromide → Di-tert-butyl (2S,4S)-2-Allyl-4-(Boc-amino)pentanedioate

Participants

Reaction Steps

To a solution of 719 mg (2.00 mmol) di-tert-butyl N-(tert-butoxycarbonyl)-L-glutamate in tetrahydrofuran (12 mL) at −78° C., lithium 1,1,1,3,3,3-hexamethyldisilazan-2-ide (1.0 M in tetrahydrofuran, 4.40 mL) was added dropwise. The solution was stirred for 30 min, then allyl bromide (0.52 mL, 6.00 mmol) was added dropwise. The reaction was stirred at −78° C. overnight and then quenched at −10° C. by the addition of 10 mL of 2 N aqueous hydrogen chloride. The mixture was warmed to room temperature poured into 10 mL 1 N aqueous hydrogen chloride and extracted with dichloromethane (3×30 mL). The organic phases were dried over magnesium sulfate and concentrated in vacuo. The crude product was purified on silica gel using a hexane/ethyl acetate gradient, and the appropriate fractions were combined and concentrated.

Provenance & Evidence