Total synthesis of eudesmane terpenes by site-selective C–H oxidations

Eudesmane terpenes: a model synthesis Organic chemists occasionally devise synthetic routes for naturally occurring molecules — called natural products — by mimicking how the molecule is synthesized by the organism that produces it. Generally, such syntheses target individual compounds, but Ke Chen and Phil Baran now report a general strategy that targets a family of structurally related compounds. Their approach mimics the 'two-phase' process observed during the biosynthesis of these terpenes — natural products that are used as flavours, fragrances, and hormones. In the first phase of the strategy, the linear hydrocarbon skeletons of the compounds are assembled and cyclized. The cyclic compounds are then subjected to a series of site-selective oxidation reactions, generating five compounds from the eudesmane family of terpenes. Adaptations of this two-phase procedure should prove effective for the synthesis of other complex terpenes.