The intramolecularly hydrogen-bonded cation, the (diacetylmethyl) tropylium ion (3), has been synthesized. The deprotonation of 3 does not afford 8, 8-diacetylheptafulvene, but does give the intramolecularly cyclized cycloheptatriene derivative, which can be transformed to the peripheral ten-π-electron cation, 5; 5 is characterized by means of 13 C NMR spectroscopy.
