Gold‐Catalyzed Sequential Cycloisomerization of 1,3,9‐Ene‐allene‐ynes to Fused Spirocarbocycles

An efficient synthetic method to prepare architecturally challenging spiro tetrahydro‐3 H ‐dicyclopenta[ a,b ]naphthalene derivatives from Au(I)‐catalyzed intramolecular sequential cycloisomerization of linear 1,3,9‐ene‐allene‐ynes is described. The proposed cycloisomerization pathway involves an initial gold‐catalyzed 1,3‐ene‐allene cycloisomerization, followed by a formal [4+2] cycloaddition to give fused spirocarbocyclic products containing a quaternary centre.