Allyl bromide → (2S,4R)-1-tert-butyl 2-ethyl 4-allyl-5-oxopyrrolidine-1,2-dicarboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of HMDS in anhydrous THF (200 mL) was added dropwise 2.5 M n-BuLi in hexane (130 mL) and the mixture was stirred at −78° C. for 1 hr. To a solution of (S)-1-tert-butyl 2-ethyl 5-oxopyrrolidine-1,2-dicarboxylate (80 g, 0.311 mol) in anhydrous THF (1600 mL) stirred at −78° C. was added lithium hexamethyldisilazide in THF. After the reaction mixture was stirred at −78° C. for 1 hr, 3-bromopropene (38.47 g, 0.318 mol) in THF (200 mL) was added and stirring was continued for 2 hr. The reaction mixture was quenched with saturated ammonium chloride solution (600 mL) at −78° C. and extracted with EtOAc (3×500 mL). The combined organic layers were dried over Na2SO4, filtered and evaporated to dryness. The crude product was separated by column chromatography to afford (2S,4R)-1-tert-butyl 2-ethyl 4-allyl-5-oxopyrrolidine-1,2-dicarboxylate (15 g, 16%).

Provenance & Evidence