Sodium hydride → tert-butyl (2S)-2-(oxiran-2-yl)pyrrolidine-1-carboxylate

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Reaction Conditions

Reaction Steps

DMSO (20 ml) was added to sodium hydride (1.55 g, NaH content 60%), and the mixture was stirred at 70° C. for 1 hour. The reaction mixture was cooled to room temperature and THF (20 ml) was added. The mixture was cooled to -5° C., and thereto was dropwise added a solution of trimethylsulfonium iodide (7.90 g) in DMSO (30 ml) over 3 minutes. After stirring for 1 minute, a solution of tert-butoxycarbonyl-L-prolinal (5.13 g) in THF (15 ml) was added quickly, followed by stirring at room temperature for 1 hour. The reaction mixture was poured into ice-water (300 ml), and extracted with chloroform. The extract was washed with saturated brine, dried over anhydrous sodium sulfate and concentrated. The residue was purified by silica gel column chromatography (eluate: hexane-ethyl acetate) to give two diastereomers of the title compound, 3.12 g of its less polar compound and 1.28 g of its more polar compound. (Configuration of the epoxy moiety of the both has not been identified.) The less polar compound was used in the following reactions.

Provenance & Evidence