13C nuclear magnetic resonance data of lanosterol derivatives--profiling the steric topology of the steroid skeleton via substituent effects on its 13C NMR.

The (13)C NMR spectra of over 24 tetracyclic triterpenoid derivatives have been structurally analyzed. The (13)C NMR chemical shifts allow one to probe the steric topology of the rigid steroid skeleton and inductive effects of its substituents. Use of deuterium labeling in chemical shift assignment and B-ring aromatic terpenoids are also featured.