Proton NMR distinguishes axial and equatorial protons in cyclohexanes

Proton NMR distinguishes axial and equatorial protons in cyclohexanes 

Coupling is a through-bond phenomenon, as we know from the couplings in cis and trans alkenes, where trans alkenes have much larger coupling constants as their orbitals are perfectly parallel. Another case of perfectly parallel orbitals occurs with trans-diaxial protons in cyclohexanes. Typical coupling constants are 10-12 Hz for trans-diaxial protons, but much smaller (2-5 Hz) for axial/equatorial and equatorial/equatorial protons. 

Interactions between different nuclei can give enormous coupling constants 

We have looked at coupling between hydrogen atoms and you may have wondered why we have ignored coupling between other NMR active nuclei. Why does not cause similar couplings  

In this section we are going to consider not only couplings between the same kind of nuclei, 

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