Ring expansion/opening reactions of epoxy ene-amides: access to azabicyclononene, tetrahydropyridine and tetrazole scaffolds

Abstract

Ene-sulfonamides, obtained from epoxy (terminal as well as internal) benzenesulfonamide and substituted chloro-acrylaldehydes, undergo Lewis acid (BF₃·OEt₂) catalysed cyclisation to afford azabicyclononene, tetrahydropyridinyl benzoate or tetrahydropyridine-carbaldehyde scaffolds depending on the substrate. In the presence of Me₃SiN₃, substituted tetrazoles are readily obtained. Key products have been characterized by single-crystal X-ray crystallography.