Ethyl nipecotate, resonance

Consider the molecule ethyl nipecotate (Figure 9.1). After we draw the molecule and number the atoms whose resonances we will assign, we can make a table with seven columns for the NMR data and another table with five columns for the NMR data (Tables 9.1 and 9.2). 

We have now assigned all of the resonances of ethyl nipecotate, and we leave as an exercise the identification of the cross peaks between the resonances from the H4 s and H5 s. 

Ethyl nipecotate contains only one nonprotonated carbon site. Because of this lack of multiple nonprotonated carbon sites, it fails to serve as a useful example for illustrating the power of the 2-D heteronuclear multiple bond correlation (HMBC) experiment in assigning the resonances from nonprotonated C s. As a general rule, a molecule with few nonprotonated carbons will rarely require data from the HMBC experiment. 

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