Nitrate radical induced oxidative, selfterminating radical cyclization cascades: Improvement of yield using a photochemical radical source

Abstract

Using the photolysis of cerium ammonium nitrate to generate nitrate radical (NO3) the alkynyl ether (1) could be cyclized through an oxidative, selfterminating radical cyclization cascade to give the tetrahydrofuran (5) in good yield. This radical source is more favorable than the earlier used anodic oxidation of lithium nitrate, because high local concentrations of oxidants are avoided.