Synthesis of high-value 1,6-enynes by tandem fragmentation/olefination.

A tandem process provides high-value 1,6-enynes that are otherwise difficult to prepare. Two base-mediated reactions-fragmentation and olefination-are executed in a coordinated manner that is overall more efficient than either reaction on its own. The 1,6-enynes can be strategically employed in conjunction with carbocyclization to deliver important targets, as noted for reported syntheses of hirsutene and illudol.