A new synthesis of pyrroles fused with polycyclic skeletons

The Diels–Alder reaction of β-sulfonylnitroethylene with cyclopentadiene, cyclohexadiene or substituted anthracenes followed by treatment with ethyl isocyanoacetate in the presence of DBU gives pyrroles fused with bicyclo2.2.1heptadiene and bicyclo2.2.2octadiene skeletons, or triptycene-types of pyrrole, respectively, which are precursors for novel porphyrins fused with polycyclic skeletons.