Tandem Michael addition - Hoffman elimination sequence of DMAD on tetrahydropyrrolo[3,2-c]pyridines. New route to vinylpyrroles

The reaction of tetrahydropyrrolo[3,2-c]pyridines with DMAD in THF at room temperature results in piperidine ring cleavage producing α- or β-vinylpyrroles in moderate to good yields. The resulting compounds are hardly available by other synthetic means and are good candidates for further transformations.