Dimethyl Sulfoxide → tert-Butyl (2S)-2-isopropyl-4-oxopyrrolidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

Oxalyl chloride (16 mL) dissolved in DCM (200 mL) was placed in a three-neck flask equipped with a stirrer and two addition funnels. One funnel contained DMSO (23 mL) in DCM (100 mL) and the other tert-butyl (2S,4R)-4-hydroxy-2-(propan-2-yl)pyrrolidine-1-carboxylate (37 g) in DCM (100 mL). The contents of the flask were cooled to −78° C., and the DMSO solution was added dropwise. After 15 minutes, tert-butyl (2S,4R)-4-hydroxy-2-(propan-2-yl)pyrrolidine-1-carboxylate was added. The reaction mixture was stirred for 30 minutes, and triethylamine (110 mL) was added. The cooling bath was removed, and water (100 mL) was added at room temperature and stirred for 10 minutes. The organic layer was separated, and the aqueous layer was extracted with DCM (3×100 mL). The combined organic layers were washed with brine (3×50 mL), dried over magnesium sulfate, filtered, and concentrated. The material was purified by silica gel chromatography (petroleum ether/ethyl acetate, 15/1) to afford tert-butyl (2S)-4-oxo-2-(propan-2-yl)pyrrolidine-1-carboxylate.

Provenance & Evidence