The positions of the double bonds in 1-phenylcyclohexadiene-1, 2-dicarboxylic acid, which had been obtained previously by the alkaline rearrangement of 2-phenyltropone-7- carboxylic acid, were elucidated from the spectral data. A similar rearrangement of tropone derivatives to dihydrobenzene derivatives was also observed. Tropone-2-carboxylic acid gave 2, 5-cyclohexadiene-1, 2-dicarboxylic acid, while 2-phenyltropone-5-carboxylic acid ...
