A novel methodology has been devised for the chemoselective reduction of enones involving the use of n Bu 3 SnH and azobisisobutyronitrile. The 1,4-reduction of variously substituted α,β-unsaturated cyclic and acyclic enones has been successfully carried out under free radical reaction conditions. The reaction has been determined to proceed via single-electron transfer. ... [Supplementary materials are available for this article. Go to the publisher's ...