NMR Studies of Closely Related Heterocyclic Molecules

This manuscript describes a laboratory exercise in our Advanced Laboratory course in which students prepare three compounds which are structurally similar, but have different substituents that make the NMR spectra all different. This allows students to visualize how structural differences affect the NMR spectra. This also allows students to see differences in stereoisomers as well as effects of phosphorus in spin-spin splitting in protons. The three molecules are all easily prepared such that the laboratory exercise can be carried out in one afternoon.