Ethanol → (2S,4S)-1-tert-butyl 2-methyl 4-bromopyrrolidine-1,2-dicarboxylate

Participants

Reaction Steps

Add triphenylphosphine (0.88 mol, 231 g) in portions to a solution of (2S,4R)-4-hydroxy-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester (0.58 mol, 144 g) and CBr4 (0.88 mol, 292 g) in dry dichloromethane (1.44 L) at 0° C. Upon complete addition, warm the reaction mixture to room temperature and stir for 4 h. Add ethanol (1.44 L) and stir for an additional 2 h. Add diethyl ether (1.44 L) to the reaction mixture, filter the precipitated triphenylphosphine oxide, and concentrate the filtrate under reduced pressure. Purify by column chromatography using 5% ethyl acetate in hexanes as eluent to obtain the title compound (155 g, 85%) as a thick oil. ES-MS m/z 308 [M+1]+.

Provenance & Evidence