Vicinal hydrogen atom shift

When complexing occurs with three jy/i-axial hydroxyl groups, it would be expected that the (equatorial) hydrogen atoms vicinal to those three hydroxyl groups would be the most affected. It was found that, in the spectrum of m-inositol (1), calcium ions cause the axial-proton signals to shift downfield somewhat more than the equatorial ones there are here, however, three a, e, a sites, in addition to the triaxial site. Mg " ions, which do not complex at the a,e,a sites (see Section III,1), cause the signals of the equatorial protons to shift twice as much as those of the axial ones. 

The enamines derived from aldehydes (Table 3) can be divided into two types. First, for those compounds where a hydrogen atom is bound to the -carbon atom the spectroscopic behaviour parallels that for the enamines derived from ketones. When the jS-carbon atom bears two substituents, its chemical shift increases. In addition to the chemical shift difference, for the allylic and )8-carbon atoms differences were noted for the coupling constants between the a-hydrogen and the allylic carbon atoms. The magnitude of the vicinal coupling constant changes with configuration and can... 

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