Policyclic Fluoranthene Hydrocarbons. 2. A New General Synthesis

Article abstract of DOI:10.1021/jo00235a005

A novel and efficient synthetic approach to policyclic fluoranthene hydrocarbons is described.The method entails fusion of an indeno ring to an appropriate alternant hydrocarbon via reaction of its aryllithium derivative with cyclohexene oxide, followed by oxidation, cyclodehydration, and aromatization.Cyclization of the cyclohexanone and cyclohexanol derivatives of the policyclic aromatic ring systems studied proceeds with high regioselectivity, and the direction of ring closure is predictable by molecular orbital methods.This synthetic approach provides a convenient general route to polyaromatic fluoranthene compounds, including potentially carcinogenic members of this class.Hydrocarbons synthesized by this method include benzacephenanthrylene (1), indeno<1,2,3-cd>pyrene (2), indeno<1,2,3-hi>chrysene (3), benzindeno<1,2,3-hi>chrysene (4), fluoreno<3,2,1,9-defg>chrysene (5), dibenzaceanthrylene (6), dibenzaceanthrylene (7), benzaceanthrylene (8), benzindeno<1,2,3-qr>chrysene (9), fluoreno<9,1,2,3-cdef>chrysene (10), and dibenzacephenanthrylene (11).