A Novel and Expeditious Approach to Unusual Spirolactam Building Blocks

Abstract
A rapid access to 7-azaspiro[4.5]decan-6-ones 1 involving three regio- and chemoselective reactions starting from tetrabromonorbornyl derivatives is described. The alkaline H2O2 cleavage reaction of monosubstituted α-diketones 9 furnished the potential bridged bicyclic lactones 10 in a highly regio- and stereoselective manner. The radical-mediated, intermolecular bridgehead C−C bond formation of the versatile bridged lactones 10 with acrylonitrile followed by LAH reduction of the adduct 13 intriguingly leads to the formation of novel spirolactam building blocks 1.