Bis(methoxycarbonyl)[2.2](2,5)pyridinophanes as nicotinamide coenzyme models

Abstract

[2.2](2,5)Pyridinophanes 1 – 4 consisting of two nicotinic ester units in the four different orientations possible were synthesized. Diquaternization to the corresponding pyridiniophanes 9 – 12 and partial reduction of 9 and 12 yielded the semi-reduced species 14 and 15; these isomers, due to their different mutual orientation of pyridinium and 1,4-dihydropyridine units, are of interest with regard to intramolecular redox reactions.