A Concise, Stereocontrolled Total Synthesis of Rippertenol

The first total synthesis of the unique terpene rippertenol, a molecule with dense stereochemical complexity arrayed on a compact framework largely devoid of functional groups, is described. Key elements include orchestrated and unique applications of aldol condensations, Diels–Alder chemistry, and a ring expansion to advance a chiral starting material containing a single chiral center into the final target in a concise and diastereocontrolled manner.