Synthesis of a bicyclic oxo-γ-lactam from a simple caprolactam derivative

The synthesis of the 6-azabicyclo[3.2.1]octane ring system, via Dieckmann cyclization, is described. Ring closure involves reaction of a caprolactam enolate with a C-6 ester, the reactive axial conformation of which is promoted by the presence of an N-tert-butyloxycarbonyl group on the lactam nitrogen. The results will enable the synthesis of new bridged caprolactams for testing as antibacterials and nucleophilic enzyme inhibitors