Gold(III)-Catalyzed Intramolecular Furanylation and Cyclopropanation of Acyclic Conjugated Enynones

Abstract

We have developed an efficient cascade gold-catalyzed furanylation-cyclopropanation of acyclic (E)-deca-2,9-dien-4-yn-1-ones and an (E)-undeca-2,10-dien-4-yn-1-one to give 1-(2-furyl)bicyclo[3.1.0]hexanes and a 1-(2-furyl) bicyclo[4.1.0]heptane, respectively. This requires a configurational change from the E-isomer to the Z-isomer prior to furan formation. The intermediate was proposed to be a gold-carbene, which would undergo cyclopropanation to furnish the product.