Ethyl chloroformate → HCID 67490821, compound

Participants

Reaction Conditions

Reaction Steps

Ethyl chloroformate (0.059 mL, 0.617 mmol) and a solution of lithium hexamethyldisilazide in tetrahydrofuran (1.0 M, 0.57 mL, 0.570 mmol) were sequentially added dropwise to a solution of (3R)-3-[1-(tert-butyldiphenylsiloxymethyl)cyclopropan-1-yl]-5-oxo-1-[(1S)-1-phenylethyl]pyrrolidine (258 mg, 0.518 mmol) in tetrahydrofuran (2 mL) at 0° C. over two minutes. The mixture was stirred at 0° C. for 30 minutes and at room temperature for 30 minutes, and a solution of lithium hexamethyldisilazide in tetrahydrofuran (1.0 M, 0.57 mL, 0.570 mmol) was further added. The mixture was stirred at room temperature for 2.5 hours and then ice-cooled. The reaction was quenched with a 10% citric acid solution (20 mL). The resulting mixture was extracted with ethyl acetate (50 mL). The organic layer was washed with water (20 mL) and brine (20 mL) and then dried over anhydrous sodium sulfate. After filtration, the solvent was evaporated under reduced pressure. Then, the resulting residue was purified by silica gel column chromatography (ethyl acetate:hexane=1:9→1:4→1:2) to give 227 mg (77%) of the title compound as a colorless transparent gummy solid.

Provenance & Evidence