Applications of two‐dimensional NMR in spectral assignments of some friedelanes and secofriendelanes

Carbon‐13 spectral assignments of three friedelanes and nineteen secofriedelanes have been made from mutual correlations, 2D X‐H correlation analyses and comparison with the carbon shifts of friedelin, which were firmly established by an INADEQUATE experiment that required reassignment of some of its resonances. Specific methyl and methine proton resonance assignments for some friedelanes, established from X‐H correlation studies, are also reported.