The preparation of 4-alkyl (or aryl) tropones has easily been accomplished by the anodic oxidation of 1-methoxy-4-alkyl (or aryl) cycloheptatrienes which were synthesized by the regioselective addition of alkyl or aryl lithium to 3-position of 7,7-dimethoxyeycloheptatriene followed by the thermal 1,5-hydrogen shift of the resulting 3-methoxy-7-alkyl (or aryl) cycloheptatrienes.
Anodic oxidation of cycloheptatrienes has been found to be one of the most powerful key tools for the preparation of a variety of non-benzenoidaromaticcompounds such as tropylium salts, tropones, tropolones, 2H-cyclohepta[b]furan-2-ones, and azulenes.