Synthesis of apara-Methoxy Substituted Tribenzocyclotriyne

Abstract
The synthesis and characterization of a methoxy substituted tribenzocyclotriyne, 1,2:5,6:9,10-tri(2,5-dimethoxyphenyl)cyclododeca-1,5,9-triene-3,7,11-triyne (2) is described. The cyclotriyne was prepared by either a Stephens-Castro or a palladium catalyzed coupling of (2-iodo-3,6-dimethoxyphenyl)ethyne. Ceric ammonium nitrate was used to demethylate 2 to form 1,2:5,6-di(2,5-dimethoxyphenyl)-9,10-(1,4-benzoquinone)cyclododeca-1,5,9-triene-3,7,11-triyne (6).