EVALUATION OF THE OLEFINIC PROTON SIGNALS IN THE H-1-NMR SPECTRA OF ALLYLIC HYDROXY-GROUPS IN LONG-CHAIN COMPOUNDS

The positional isomers of monounsaturated long-chain fatty compounds c ontaining allylic hydroxy groups (shown for trans double bonds) are di stinguished by H-1-NMR spectroscopy through the chemical shift differe nces of the olefinic protons. These differences are expressed as ratio nal functions (the differences being proportional to the negative thir d power of the position of the unsaturation), or logarithmic functions (the differences being proportional to the position of the unsaturati on raised as power). The present results on more sensitive H-1-NMR spe ctra complement previous work on the C-13-NMR spectra of these compoun ds. Theoretical models for explaining shifts in C-13-NMR therefore als o apply to H-1-NMR.