Ammonium Chloride → (1S,5R)-5-Fluoro-4-oxo-3-[(1R)-1-phenylethyl]-3-azabicyclo[3.3.0]octan-1-ylcarboxylic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

(3S)-3-(3-benzenesulfonyloxy-1-propyl)-4-Fluoro-5-oxo-1-[(1R)-1-phenylethyl]pyrrolidine-3-carboxylic acid tert-butyl ester (10.9 g) was dissolved in tetrahydrofuran (350 mL), and the atmosphere was replaced with argon. Then, potassium hexamethyldisilazide (0.5 M solution in toluene) (86.5 mL) was added dropwise at −15° C., and the mixture was stirred at 0° C. for 1.5 hours. After cooling to −10° C., saturated aqueous ammonium chloride (100 mL) was added dropwise, and the mixture was stirred at room temperature for 30 minutes. The reaction solution was extracted with a 10% citric acid solution and ethyl acetate. Then, the organic layer was washed with brine, dried over anhydrous sodium sulfate, and filtered. Thereafter, the solvent was evaporated under reduced pressure. The residue was subjected to silica gel column chromatography (hexane:ethyl acetate=9:1→7:1) to give 4.36 g of the title compound as a pale yellow solid.

Provenance & Evidence