Trifluoroacetic acid → cis-2-Benzylhexahydrocyclopenta[c]pyrrol-4(1H)-one

Participants

Reaction Conditions

Reaction Steps

A round bottom flask purged with argon was charged with N-benzyl-1-methoxy-N-(trimethylsilylmethyl)methanamine (31.2 g, 131.4 mmol) and cyclopent-2-ene-1-one (9.0 g, 9.2 mL, 109.5 mmol). The reaction mixture was cooled to 0° C. and a solution of trifluoroacetic acid (1.25 g, 847 μL, 11.0 mmol) in DCM (11 mL) was added to it. The reaction mixture was stirred at 0° C. for 4 h, warmed to room temperature and stirred for 18 h. The reaction was quenched by the addition of saturated sodium bicarbonate and the layers were separated. The aqueous layer was extracted with DCM and the combined organic layers was washed with brine, dried over sodium sulfate and concentrated under reduced pressure. The crude material was purified via silica gel column chromatography using 40 to 80% EtOAc in hexanes to obtain (3aR,6aS)-2-benzyl-1,3,3a,4,5,6a-hexahydrocyclopenta[c]pyrrol-6-one (19.8 g, 84%) as a light yellow oil.

Provenance & Evidence