Abstract Unsaturated ϵ-lactams undergo a novel process involving a skeletal reorganization to give fused pyrrolidine-lactones by reaction with aromatic α-bromo ketones in the presence of 1, 4-diazabicyclo [2.2. 2] octane and a base. The process involves the formation of an ammonium salt and subsequently a nitrogen ylide, which initiates the rearrangement reaction. This species reduces undesired side-reactions such as double-bond shifts or ...
