The synthesis of 7-(substituted-amino)-3-azabicyclo[3.2.0] heptanes

1,2-Cycloaddition reactions of several enamines with N-substituted maleimides and 4-phenyl-1,2,4-triazoline-3,5-dione have been carried out. The adducts were transformed into 7-(substituted-amino)-3-azabicyclo[3.2.0]heptanes and a 1,2,4-triazolidine-1-acetaldehyde, respectively. These are the first reported examples of 3-azabicyclo[3.2.0]heptanes substituted in any position other than the 3-position. The reaction of an ynamine with N-benzylmaleimide afforded a bicyclic intermediate which upon hydrolysis gave a 2,5-dioxo-3-pyrrolidineacetic acid.