Synthesis of N-BOC-3-azabicyclo[3.3.0]octan-7-one via reductive pauson-khand cyclization and subsequent conversion to a novel diazatricyclic ring system

An intramolecular reductive Pauson-Khand reaction of the hexacarbonyldicobalt complex of N-(tert-butyloxycarbonyl)allylpropargylamine under dry-state adsorption conditions directly afforded the saturated N-BOC-3-azabicyclo[3.3.0]octan-7-one when the reaction was performed under an inert atmosphere. This bicyclic ketone was converted in several steps to the novel octahydro-1-azeto[2′,3′:3,4]cyclopenta[1,2-C]pyrrole ring system as confirmed by single crystal X-ray analysis.