[O:1]=[C:2]([CH3:8])/[CH:3]=[CH:4]/[C:5](Cl)=[O:6].[CH2:9]([NH:11][CH2:12][CH3:13])[CH3:10]>CCOCC>[CH2:9]([N:11]([CH2:12][CH3:13])[C:5](=[O:6])/[CH:4]=[CH:3]/[C:2](=[O:1])[CH3:8])[CH3:10]To flame dried flask containing (E)-4-oxo-2-pentenoyl chloride (1.16 g, 8.76 mmol) in ether cooled to -15° C. is added diethylamine (1.41 g, 19.28 mmol) in ether (5 ml) and stirred for 2 hours while being warmed to ambient temperature. The solvents are removed in vacuo, and chromatographed on silica gel (230-400 mesh, 100 ml), eluting with hexane/ethyl acetate (75/25). The appropriate fractions are combined (Rf =0.31, TLC, hexane/ethyl acetate, 25/75) and concentrated in vacuo to give the title compound, NMR (CDCl3) 7.15, 7.04, 3.45, 3.40, 2.33, 1.20, 1.15.
Wird geladen…