Multisubstituted naphthalene synthesis from 4-hydroxy-2-pyrones through [4+2] cycloaddition with o-silylaryl triflates

Abstract

An efficient synthetic method for multisubstituted naphthalenes from 4-hydroxy-2-pyrones through cycloaddition with aryne intermediates is disclosed. Various highly functionalized 2-pyrones were synthesized through 4-hydroxy-2-pyrones in short steps. The resulting 2-pyrones reacted smoothly with a wide range of aryne intermediates generated from o-silylaryl triflates to provide multisubstituted naphthalenes by the Diels–Alder reaction and following decarboxylative aromatization. The aryne reaction of 2-pyrones served in the synthesis of diverse naphthalenes having 1,2,3-triazole moieties by combination with triazole formation of 4-azido-2-pyrones.