Intramolecular Radical Rearrangement Reactions of 2-Methyleneaziridines: Application to the Synthesis of Substituted Piperidines, Decahydroquinolines, and Octahydroindolizines

[reaction: see text] Intramolecular 5-exo cyclization of 3-(2-methyleneaziridin-1-yl)propyl radicals leads to the generation of a highly strained, bicyclic aziridinylcarbinyl radical that undergoes C-N bond fission to the ring-expanded aminyl radical. This methodology provides access to substituted 3-methylenepiperidines and, by combining it with an additional 5-exo-trig cyclization reaction, the octahydroindolizidine skeleton.