The type 2 imino Diels-Alder cycloaddition was used for the synthesis of a homologous series of bridgehead olefin/bridgehead lactams. The X-ray crystal structures of three members of this series, including the highly strained 2-carbomethoxy-8-oxo-2-azabicyclo[3.3.1]non-4-ene, were obtained. An analysis of the structural data permits evaluation of the responses of the bridgehead double bond and bridgehead amide linkages to similar torsional distortions.