Syntheses of Cyclic Oximes via Radical Ring Closure

Significance

Radical carbocyclization reactions were successfully performed on O-trityl oximes using diphenyldiselenide (Ph₂Se₂) as key factor. The trityl leaving group is hereby assumed to become a persistent radical which aborts the course of the reaction. In the presence of minor amounts of Ph₂Se₂, PhSeH is formed on reaction with Bu₃SnH. PhSeH is a much more efficient hydrogen donor than Bu₃SnH and is capable of trapping the trityl radical, thus reinitiating the radical process.