Syntheses and Properties of Pentatrideca-, Pentapentadeca-, Pentaheptadeca-, and Pentanonadecafulvalene Derivatives

Abstract

5,10-Dimethyl-6,8-bisdehydropentatridecafulvalene 11, 10-methyl-6,8-bisdehydro-4,5-benzopentatridecafulvalene 12, 6,8-bisdehydro-4,5:10,11-dibenzopentatridecafulvalene 13, 5,10-dimethyl-6,8-bisdehydropentapentadecafulvalene 14, 7,12-dimethyl-8,10-bisdehydropentaheptadecafulvalene 15, and 7,12-dimethyl-8,10-bisdehy-dropentanonadecafulvalene 16 were synthesized through the reaction of the corresponding bisdehydroannulenones 1–6 with cyclopentadienide. The tropic nature of these pentafulvalenes is discussed on the basis of 1H NMR and electronic spectra as well as those of the corresponding heptafulvalene derivatives.