反应详情

In a 20 mL scintillation vial, ((R)-1-methyl-2-oxo-ethyl)-carbamic acid tert-butyl ester (2.5 g, 14.4 mmol) and (triphenylphosphoranylidene)acetonitrile (6.52 g, 21.7 mmol) were mixed in dichloromethane (20 mL) and stirred at room temperature for 16 h. The solvent was evaporated to give the crude material, which was purified by column chromatography (silica gel, gradient n-hexanes ethyl acetate) to provide 1.8 g (63%) of ((R)-3-cyano-1-methyl-allyl)-carbamic acid tert-butyl ester in a 3:1 diastereoselectivity (E:Z) as a colorless oil. 1H NMR (300 MHz, CDCl3) δ ppm 6.38-6.79 (m, 1H), 5.47 (dd, J=16.24, 1.89 Hz, 1H), 4.48 (bs, 1H), 4.47 (bs, 1H), 1.45 (s, 1H), 1.28 (d, J=7.18 Hz, 9H).

1. customThe solvent was evaporated
2. customto give the crude material, which
3. customwas purified by column chromatography (silica gel, gradient n-hexanes ethyl acetate)