A regioselective Wagner–Meerwein rearrangement directed towards the six-membered ring of the longipinane skeleton

A Wagner–Meerwein rearrangement was selectively promoted towards the six-membered ring of (1R,3S,4S,5S,7R,9R,10R,11R)-7,9-diacetyloxy-1-hydroxylongipinane () to generate a series of compounds which contain a new carbocyclic skeleton named uruapane. Their structures were elucidated by 1D and 2D NMR data in combination with the X-ray diffraction analysis of . Molecular modeling was used to study the reaction mechanism and deuterium labeling was employed to confirm two consecutive hydride shifts which occurred during formation of .