Acetic Acid → (3S)-4-Fluoro-3-(2-hydroxyethyl)-5-oxo-1-[(1R)-1-phenylethyl]pyrrolidine-3-carboxylic acid tert-butyl ester

Participants

Reaction Steps

Acetic acid (0.66 mL, 11.54 mmol) and a 1 M solution of tetrabutylammonium fluoride in tetrahydrofuran (8.3 mL, 8.3 mmol) were sequentially added to a solution of the crude (3S)-3-[2-(tert-butyldimethylsilyloxy)ethyl]-4-fluoro-5-oxo-1-[(1R)-1-phenylethyl]pyrrolidine-3-carboxylic acid tert-butyl ester (3.44 g) in tetrahydrofuran in a nitrogen atmosphere at 0° C. After stirring at room temperature for 20 hours, the reaction solution was poured into a mixture of ethyl acetate (100 mL) and a saturated sodium bicarbonate solution (50 mL), followed by extraction with ethyl acetate (200 mL). The organic layer was washed with brine (50 mL×2), and then dried over anhydrous sodium sulfate and filtered. The filtrate was then concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (hexane:ethyl acetate=1:1) to give 2.06 g (91%, two steps) of the title compound as colorless crystals.

Provenance & Evidence