Conversion of γ-bicyclic lactams to 4,5-dihydro-2H-pyridazin-3-ones

Bicyclic lactams are uniquely suited as precursors for the synthesis of chiral substituted 4,5-dihydro-2H-pyridazinones. This paper describes the development of a method for the direct conversion of unsubstituted and 4-substituted γ-bicyclic lactams to 4,5-dihydro-2H-pyridazin-3-ones and 2-phenyl-4,5-dihydro-2H-pyridazin-3-ones.