2,3,5,6‐tetramethylmorpholine. VI. Cyclization of N‐substituted 3,3′‐iminobis‐2‐butanols

Abstract

The cyclization of N‐substituted 3,3′‐iminobis‐2‐butanols to N‐substituted 2,3,5,6‐tetramethylmorpholines in sulfuric acid is studied. The ring closure seems to be exclusively a normal SN2‐type substitution with partial inversion of configuration before the cyclization. The steric influence of the N‐substituents on the SN2‐reaction and on the inversion is discussed.