反应详情

A stirring mixture of 2-allylcyclopentanone (0.993 g, 8 mmol) and ammonium acetate (1.54 g, 20 mmol) in 2,2,2-trifluoroethanol (2.5 mL) was treated with t-butyl isocyanide (1.81 mL, 16 mmol). The reaction mixture was stirred at room temperature for 4 days, following which the mixture was dissolved in a minimum amount of dichloromethane and purified by flash column chromatography (silica gel, 60% ethyl acetate in heptane) to afford the anti-isomer of (1S,2S)-1-acetamido-2-allyl-N-tert-butylcyclopentane carboxamide (0.771 g, 36%) as a white solid. The later migrating syn-isomer is obtained as a white solid (0.851 g, 40%), by increasing the concentration of the polar solvent ethyl acetate to 80%. Anti-isomer: 1H NMR (CDCl3, 300 MHz) δ 7.26 (br s, NH, 1 H), 6.82 (br s, NH, 1 H), 5.88-5.72 (m, 1 H), 5.07 (br d, J=17 Hz, 1 H), 5.00 (br d, J=12 Hz, 1 H), 2.56-2.41 (m, 1 H), 2.36-2.17 (m, 3 H), 2.01 (s, 3 H), 1.97-1.81 (m, 2 H), 1.72-1.60 (m, 2 H), 1.32 (s, 9 H); MS (+CI): m/z for C15H26N2O2: expected 266.2; found 266.2 (M+H)+

1. custompurified by flash column chromatography (silica gel, 60% ethyl acetate in heptane)