The bromiation of 4H-cyclopenta [deflphenanthrene gave the 1-bromo derivative as a main product accompanied by small amounts of 3-and 8-bromo isomers. The hydrocarbon was transformed into 4-bromo-and 8, 9-di-bromo-8, 9-dihydro-4H-cyclopenta [deflphenanthrene by radical bromination under exposure to light. Additionally, the reaction of 8, 9-dihydro-4H- cyclopenta [deflphenanthrene and cyclopenta [deflphenanthren-4-one with bromine ...