The NMR spectra and conformations of cyclic compounds–III: The conformations of some pinane derivatives

The 220 MHz 1H spectra of isoverbanone, nopinone and verbanone are reported. The spectra of the first two are completely assigned but that of verbanone only partially. The coupling constants obtained provide information about the conformation of these molecules. The isoverbanone molecule is almost Y shaped, but that of nopinone is between a Y shape and a half‐chair conformation with the six membered ring bent away form the gem dimethyl groups. These conformations are consistent with the known steric interactions in these molecules.