Synthesis of Fencholenic Aldehyde from α-pinene Epoxide on Modified Clays

The conditions for isomerization of α-pinene epoxide (2,3-epoxypinane) on modified clays that gave comparatively high contents (33.0%) of fencholenic (iso-campholenic) aldehyde in the product mixture were determined. An effective method for isolating it was proposed. The structure of iso-campholenic aldehyde was confirmed by analyzing 2D NOESY and HMBC NMR spectra.