Tandem Enyne Metathesis−Metallotropic [1,3]-Shift for a Concise Total Syntheses of (+)-Asperpentyn, (−)-Harveynone, and (−)-Tricholomenyn A

A tandem reaction sequence involving relay metathesis-induced enyne RCM and metallotropic [1,3]-shift is an effective tool to construct cyclic alkenes with embedded 1,5-dien-3-yne moieties from acyclic precursors containing a 1,3-diyne. Total syntheses of (+)-asperpentyn, (−)-harveynone, and (−)-tricholomenyn A have been accomplished by implementing this metathesis-based tandem reaction sequence as the key step.