Stereocontrolled preparation of bicyclic alkaloid analogues: an approach towards the kinabalurine skeleton

An approach towards the construction of bicyclic analogues of monoterpene alkaloids belonging to the kinabalurine, incarvilline and skytanthine families of natural products is reported. These syntheses rely on a stereoselective intramolecular Pauson–Khand cyclisation of a chiral pool-derived enyne in order to prepare the bicyclic core. Stereoselective further elaboration generates diastereomeric analogues of the naturally occurring alkaloids.