C-C bond migration in the cycloisomerization of oxygen-tethered 1,6-enynes

A C-C bond migration event during the cycloisomerization of 1,6-enynes is described. Two different catalytic systems, iridium- or platinum-based, are able to induce this process. Alkyl migrations of larger rings and acyclic groups indicate that the reaction is not fully driven by the release of ring strain.