III anthracene (I). This compound, on catalytic intramolecular dehydrogenation, might lead to dibenzo-[aelperylene (IT) and/or naphtho [2, 1-a] perylene (111). When I was dehydrogenated with aluminum chloride and stannic chloride, only one perylene derivative was found. In order to establish the structure of the product, which was either I1 or 111, we undertook an unequivocal synthesis of naphtho [2, 1-a] perylene (111). On the basis of ...