反应详情

While under nitrogen, a mixture of tert-butyl 3-allyl-4-oxocyclopentylcarbamate, mixture of isomers (1.08 g, 4.5 mmol) and ammonium acetate (1.39 g, 18 mmol) in 2,2,2-trifluoroethanol (5 mL) was treated with t-butylisonitrile (1.53 mL, 13.5 mmol) and stirred at room temperature for 3 days. The reaction mixture was concentrated in vacuo and dissolved in dichloromethane (50 mL). The solution was washed with water (25 mL), dried (Na2SO4), and added to a silica gel column (˜250 cc). This was eluted successively with 50%, 65%, 70%, and 75% ethyl acetate in heptane to afford tert-butyl (1S,3S,4S)-3-acetamido-4-allyl-3-(tert-butylcarbamoyl)cyclopentylcarbamate (0.99 g, 58%) as a white solid. NMR (CDCl3): δ 7.72 and 7.04 (br s, 1 H combined), 7.27 and 6.35 (br s, 1 H combined), 5.84 and 5.06 (br s, 1 H combined), 5.55-5.70 (m, 1 H), 4.85-4.95 (m, 2 H), 3.90-4.15 (m, 1 H), 2.10-2.90 (m, 4 H), 1.70-2.00 (m, 6 H), 1.20-1.40 (m, 18 H). MS (M+1): 382.2.

1. concentrationThe reaction mixture was concentrated in vacuo
2. dissolutiondissolved in dichloromethane (50 mL)
3. washThe solution was washed with water (25 mL)
4. dry with materialdried (Na2SO4)
5. additionadded to a silica gel column (˜250 cc)
6. washThis was eluted successively with 50%, 65%, 70%, and 75% ethyl acetate in heptane