The (Z)/(E)‐configurational analysis of isolated double bonds in pheromones and unsaturated fatty acids. The use of 1D and 2D J‐resolved 1H CW off‐resonance techniques in 13C NMR spectroscopy

The 1H CW off‐resonance decoupled 13C NMR spectra of pheromones and unsaturated fatty acids were measured for the determination of the configuration of double bonds of the type CH2CH  CHCH2. The decoupling frequency corresponded to the resonance frequency of the CH2 protons. The 2nd order splittings in the observed multiplets of the olefinic carbon atoms allow an approximate determination of the vicinal coupling constant between the olefinic protons, and the configurational assignment of the double bond.