Abstract

The based-promoted rearrangements of quaternary ammonium salts can be divided into two categories. In the Stevens rearrangement one-alkyl group migrates from the quaternary nitrogen group to the alpha carbon atom of a second alkyl group. The Somelet-Hayser rearrangement involves migration to the ortho position of a benzyl quaternary ammonium salt. When structurally feasible, both rearrangements may occur simultaneously although experimental conditions markedly affect the competing pathways.