Acetic Acid → HCID 86664659, compound

Participants

Reaction Steps

Under nitrogen atmosphere, to a solution of tert-butyl (3S)-3-[3-(tert-butyldimethylsilyloxy)propan-1-yl]-5-oxo-1-[(1R)-1-phenylethyl]pyrrolidine-3-carboxylic acid (960 mg, 2.08 mmol) in THF (15 mL) was added 1.0M lithium bis(trimethylsilyl)amide in THF solution (2.29 mL, 2.29 mmol) at −78° C., and the mixture was stirred for 30 minutes. Then, N-chlorosuccinimide (333 mg, 2.50 mmol) added and the mixture was stirred for 1 hour at −60° C., and further stirred for 10 minutes at 0° C. To the mixture were added saturated aqueous solution of ammonium chloride and ethyl acetate. The separated organic layer was washed with water and brine. The solution was dried over anhydrous sodium sulfate, and the solvent was distilled off under reduced pressure. At 0° C., to a solution of this residue in THF (20 mL) were added acetic acid (0.24 mL, 4.16 mmol) and 1.0M tetrabutylammonium fluoride in THF solution (4.16 mL, 4.16 mmol), the mixture was stirred for 16 hours at room temperature. To the mixture were added 10% aqueous solution of citric acid and ethyl acetate. The separated organic layer was washed with water and brine. The solution was dried over anhydrous sodium sulfate, and the solvent was distilled off under reduced pressure. The residue was purified by silica gel flush column chromatography (ethyl acetate/hexane=1:1→1:2) to afford 506 mg of the title compound as a pale yellow oil.

Provenance & Evidence