2,3,5,6‐tetramethylmorpholine. V. Mechanism study of cyclization of 3,3′‐iminobis‐2‐butanols

Abstract

The mechanism of cyclization of 3,3′‐iminobis‐2‐butanols to 2,3,5,6‐tetramethylmorpholines in sulfuric acid is studied. Contrary to our prior suggestions, the ring closure seems to be exclusively a normal S N 2‐type substitution. The partial inversion before the cyclization is discussed.