One-Step Synthesis of Naphthofurandione, Benzofurandione, and Phenalenofuranone Derivatives by the CAN-Mediated Cycloaddition

The 3+2-type cycloaddition reaction of 2-hydroxy-1,4-naphthoquinones with various alkenes or phenylacetylene was mediated by ammonium cerium(IV) nitrate (CAN) to give the corresponding naphtho[2,3-b]furan-4,9-dione and naphtho[1,2-b]furan-4,5-dione derivatives. The reaction of 2-hydroxy-1,4-benzoquinones with alkenes in the presence of CAN similarly proceeded to give benzofuran-4,7-dione and benzofuran-4,5-dione derivatives. 3-Hydroxy-1H-phenalen-1-one also underwent the CAN-mediated cycloaddition with alkenes or phenylacetylene to give the corresponding 7H-phenaleno[1,2-b]furan-7-one derivatives.