Mimicking Nature in Reshaping the Triterpene Skeleton: Synthesis of a Class of Unnatural Oleanane Derivatives

The possibility of duplicating the efficiency and selectivity of natural processes under laboratory conditions remains a significant challenge for organic chemists. In this letter, we demonstrated that it is possible to introduce pinpoint modifications and to reshape the terpene skeleton of easily available oleananes in a biomimetic fashion. Furthermore, aromatization of the A ring of the triterpene system is reported here for the first time, mimicking what occurs exclusively in nature in sediments.