Photodehydrocyclizations of stilbene-like compounds VII: Synthesis and properties of the double helicene, diphenanthro[3,4-c;3′,4′-l]chrysene

A description of two alternative routes (Schemes 1 and 2) for the synthesis of the title compound (I) is given. Only the second route resulted in the formation of the two diastereomers of I. The physical properties of both isomers are given. The reacemization is discussed.