Rhodium‐Catalyzed [5+2] Cycloaddition of 3‐Acyloxy‐1,4‐enyne with Alkene or Allene

We recently developed a completely new type of Rh‐catalyzed 5+2] cycloaddition by using 3‐acyloxy‐1,4‐enyne (ACE) as the 5‐carbon building block. In this update, we show that ACE can undergo intramolecular 5+2] cycloaddition with either an alkene or an allene in the presence of an appropriate rhodium catalyst and ligands to afford bicyclic compounds with multiple stereogenic centers. In most cases, cis‐fused bicyclo5.3.0]decadienes are prepared highly diastereoselectively.