Synthesis of fused carbocycles via a selective 6-endo dig gold(I)-catalyzed carbocyclization.

A gold-catalyzed synthesis of fused carbocycles via a regioselective 6-endo dig process is reported. The selectivity can be modulated by the steric and electronic properties of gold(I) complexes. The ligands can influence the pathway selectivity for the first bond formation rather than through a common intermediate generated after an initial bond formation. This gold(I)-catalyzed transformation provides access to synthetically useful carbocyclic motifs that are found in numerous diterpenoid natural products.