Total Synthesis of (+)‐Omphadiol

A smooth transition from (R)-carvone to a β-lactone and then to (+)-omphadiol characterizes the first total synthesis of this sesquiterpene, which was achieved in ten steps and 18 % overall yield. All six contiguous stereogenic centers were introduced in a highly diastereoselective manner. Key steps include a nucleophile-promoted aldol lactonization, a single-pot, sequential intra-/intermolecular dialkylation, a tandem olefin isomerization/RCM, and a cyclopropanation with unusual facial selectivity.