Hydrochloric Acid → cis-2-Benzylhexahydrocyclopenta[c]pyrrol-4(1H)-one

Participants

Reaction Steps

(S,E)-N-((3aS,6aR)-2-Benzylhexahydrocyclopenta[c]pyrrol-4(5H)-ylidene)-2-methylpropane-2-sulfinamide (2.67 g, 8.38 mmol) from Example 14 Step A and 2.0 N aqueous HCl (18.86 mL, 37.7 mmol) were combined in tetrahydrofuran (25 mL). The reaction was stirred at room temperature for 2 hours and the tetrahydrofuran was removed in vacuo and the remaining aqueous portion was made slightly basic with aqueous sodium bicarbonate solution. The aqueous layer was extracted with 3×200 mL of dichloromethane. The combined organic layers were separated, and the solvent was removed in vacuo. The crude material was purified on a silica gel cartridge (Analogix®, Burlington, Wis., RS25-25) eluting with 5-50% ethyl acetate/hexanes to give (3aS,6aR)-2-benzylhexahydrocyclopenta[c]pyrrol-4(5H)-one: 1H NMR (300 MHz, CDCl3) δ ppm 7.35-7.16 (m, 5H), 3.61 (d, J=13.1, 1H), 3.48 (d, J=13.1, 1H), 3.02 (dd, J=1.8, 9.1, 1H), 2.96-2.82 (m, 1H), 2.71-2.56 (m, 2H), 2.43 (dt, J=8.2, 17.4, 3H), 2.34-2.21 (m, 1H), 2.12 (ddd, J=8.3, 13.0, 16.9, 1H), 1.79 (dddd, J=4.2, 6.4, 9.2, 13.2, 1H).

Provenance & Evidence