The tropylium cation has been treated with the hindered bases triphenylmethyl sodium, 2,6-dimethoxy-phenyl lithium, and 2,4,6-tri-t-butylphenyl lithium to give substituted cycloheptatrienes. Where possible its reaction with tertiary amines follows Reaction Scheme 1 to give immonium salts which can be hydrolyzed to tropylated aldehydes and ketones. Its reaction with trimethylamine gives the quaternary ammonium salt which on exposure to the atmosphere is decomposed to trimethylammonium fluoborate and a mixture of tropone and ditropyl ether.