Reverse Cope Elimination Reactions. 1. Mechanism and Scope

Article abstract of DOI:10.1021/jo00123a013

N-4-Pentenyl- and N-5-hexenyl-N-methylhydroxylamine cyclized under mild conditions in a reverse Cope elimination reaction to give 1,2-dimethylpyrrolidine N-oxide and 1,2-dimethylpiperidine N-oxide, respectively.The reaction was shown to be concerted and thermodynamically controlled.The scope of this novel cyclization is discussed, and comparisons are made with the closely related and previously reported cyclization of monosubstituted alkenylhydroxylamines to give cyclic hydroxylamines.