A shorter synthesis of symmetrical 2,11-dimethyl-bis-Tröger`s bases. A new molecular tweezer

Abstract

This paper reports a new synthesis of 2,11-dimethyl-bis-Tröger´s bases starting from pphenylenediamine.The new synthesis is more efficient than those previously described and yields the anti isomer in much higher yield.Isomerization in acidic medium of the anti isomer allowed us to obtain for the first time the syn isomer, a new molecular tweezer.