OBJECTIVES: The synthesis in 5-15 g amounts of derivatives of benz(a)anthracene, methylcholanthrene, and benzo(a)pyrene which will throw more light on the effect of structure on their carcinogenic and mutagenic potency. These derivatives may elucidate the carcinogenic and/or detoxification metabolism involved in their interaction with experimental animals or enzyme systems. Our work will be strictly synthetic using methods previously developed or improved in our laboratory. All testing will be done by biological scientists such as J. A. and E. C. Miller (Wisconsin), C. Huggins (Chicago) and R. Hart (Ohio State).