Protons on saturated carbon atoms

We shall start with protons on saturated carbon atoms. The top half of the diagram below shows how the protons in a methyl group are shifted more and more as the atom attached to them gets more electronegative. 

Proton chemical shifts tell us about chemistry 

What we need is a quick guide rather than some detailed correlations, and the simplest is this all functional groups except very electron-withdrawing ones shift methyl groups from 

1 ppm (where you find them if they are not attached to a functional group) downfield to about 

Very electron-withdrawing groups shift methyl groups to about 3 ppm. This is the sort of thing it is worth learning. 

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The integration gives useful—indeed essential—information, but it is much more important to understand the reasons for the exact chemical shift of the different types of proton. In the last example you can see one marked similarity to carbon spectra protons on saturated carbon atoms next to oxygen are shifted downfield to larger 5 values (here 3.3 and 3.9 p.p.m.). The other regions of the proton NMR spectrum are also quite similar in general outline to those of 13C spectra. Here they are. 

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