"Dewar Benzene" and Benzene
It is sometimes incorrectly claimed that Dewar proposed his structure as the true structure of benzene. In fact Dewar merely wrote the structure as one of seven possible isomers, and believed that his experiments on benzene supported the (correct) structure which had been proposed by Kekulé.
After the development in 1928 of the valence bond theory, the three possible Dewar structures were considered as minor resonance contributors in the overall description of benzene. The major resonance contributors are of course the two possible Kekulé structures.
Other classic structures which have been considered as possible benzene isomers are prismane, benzvalene and Claus' benzene. Prismane and benzvalene were synthesized in the 1970s; Claus' benzene is impossible to synthesize.
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