Benzannulated Isobenzofurans

Abstract

A number of arynes, generated by treatment of haloarenes with sodium or potassium amide in tetrahydrofuran, were trapped with furan. The resulting dihydro epoxy arenes were converted into the following annulated isobenzofuran derivatives by using reverse Diels-Alder methodology: naphtho[l,2-clfuran, phenanthro[9,10-elfuran, pyreno[l,2-elfuran, pyreno[3,4- elfuran, anthra[l,2- elfuran, phenanthro[l,2- clfuran and phenanthro[3,4- elfuran. Bimolecular rate constants for the addition of maleic anhydride to these furans were measured, and were correlated with the Herndon structure count. Addition of arynes to selected members of this furan series yielded adducts which were deoxygenated to afford polycyclic aromatic hydrocarbons.