Two-dimensional NMR studies of cyperene

Combined utilization of 1H1H homonuclear and 1H13C heteronuclear NMR chemical shift correlations, two-dimensional J-resolved 1H NMR measurements and homonuclear 1H double resonance experiments allowed specific assignments for both 1H and 13C NMR frequencies to be made for the tricyclic sesquiterpene cyperene. The results also provided information on the conformation of the six-membered ring of this natural product, which was recognized as a distorted chair.