Method for estimating ¹³ C NMR chemical shifts in sp3 hybridized C atoms as a simple NMR teaching strategy

By observing the chemical shifts of Z / cis and E / trans of small groups such as alkyl (methyl, methylene), and hydroxyl groups, their determination of the configuration can be determined via shielding effect between neighboring groups. Such effect is a shielding relationship between the groups which are close to each other in space. Their proximity in space can be confirmed by correlations in the ¹ H – ¹ H NOESY NMR (nuclear overhauser effect spectroscopy nuclear magnetic resonance) spectra. This one approach would be helpful in assisting students in learning to answer simple NMR spectra problems, such as laboratory activities, repositories of practice problems, and collaborative learning activities. The shielding effect is that “The neighbor groups in space, for example, Z or cis groups, shield each other and consequently resonate at higher upfield shifts in the ¹³ C-NMR; vice versa for the E or trans groups and hence resonate at lower downfield shifts”.