A two-pronged study of a series of 2-aryl-4, 6-dinitrobenzotriazole 1-oxide substrates (2a c) is reported: Diels Alder type pericyclic reactivity and covalent hydration to yield Meisenheimer type hydroxy anionic σ-adducts. The most activated benzotriazole 1-oxide 2a is found to exhibit both dienophilic and heterodienic behaviour on treatment with cyclopentadiene, providing a highly functionalized stereoselective diadduct (7). This ...
