Dimethyl Sulfoxide → (4S,7S,11aR)-7-tert-butoxycarbonylamino-6-oxo-1,3,4,6,7,8,11,11a-octahydro-2H-pyrido[1,2-a]azocine-4-carboxylic Acid Methyl Ester

Participants

Reaction Steps

6-Allyl-1-(2-tert-butoxycarbonylamino-pent-4-enoyl)-piperidine-2-carboxylic acid methyl ester, 40, (1.0 g, 2.6 mmol) is dissolved in dichloromethane (100 mL). Grubbs catalyst (0.5 g, 0.61 mmol) is added and the mixture is heated at reflux for 24 hours. The reaction is cooled and dimethylsulfoxide (2 mL) is added. After 24 hours, the solution is concentrated to a oil, which is purified over silica (ethyl acetate/hexanes) to afford 680 mg of the desired product. 1H NMR (CDCl3) δ 6.02 (d, J=6.6 Hz,1H), 5.61 (m, 1H), 5.21 (m, 1H), 4.93 (ddd, J=6.6, 6.2, 6.2 Hz, 1H), 4.54 (m, 1H), 3.71 (s, 3H), 2.95 (ddd, J=16.2, 5.9, 5.9 Hz, 1H), 2.63 (ddd, J=17.6, 12.0, 5.5 Hz,1H), 2.42 (ddd, J=16.2, 5.8, 5.1 Hz, 1H), 2.34–2.16 (m, 2H), 1.90–1.58 (m, 5H), 1.48 (s, 9H); 13C NMR δ 173.0, 172.5, 155.6, 129.2, 125.0, 79.9, 52.4, 52.0, 51.2, 50.8, 36.6, 34.5, 30.1, 28.8(3C), 26.4, 16.0.

Provenance & Evidence