Gold(I)-Catalyzed Formation of Naphthalene/Acenaphthene Heterocyclic Acetals

A gold-catalyzed addition/cyclization reaction to form 3-alkoxy-benzo[de]isochromene derivatives was developed. All reactions, performed in mild conditions, exhibited high regioselectivity and good to excellent reaction yields. Additionally, optimized methodology was used in total synthesis of 2-phenylphenalenone, an alleged natural product found in Macropidia fuliginosa plant.