Benzenoid <i>versus</i> Annulenoid Aromaticity: Synthesis and Properties of Kekulene

Abstract

Kekulene, a kind of “super-benzene”, is a compound suitable for distinguishing between annulenoid (1a) and benzenoid aromaticity (1b). It has now proved possible to synthesize kekulene and to record the 1H-NMR spectrum of this highly insoluble compound. The spectrum is interpreted as supporting the benzenoid form (1b).