The [2, 3]-sigmatropic rearrangements of ammonium ylids derived from 1, 2, 5, 6- tetrahydropyridine have been studied: both rearrangement and elimination processes are observed, with rearrangement favoured when aprotic solvents are used in the reaction. The presence of anion-stabilizing substituents on the nucleophilic carbon atom of the intermediate ylid species involved in the tranformation also engenders rearrangement; ...
