Synthesis of a Series of Novel Polycyclic Aromatic Systems: Isomers of Benzanthracene Containing a Cyclopenta-Fused Ring

Article abstract of DOI:10.1021/jo00158a012

The four possible isomers of benzanthracene containing a cyclopenta-fused ring have been synthesized and characterized.These systems are of interest for structure-activity studies in bioactivation because of their predicted high level of activity.Formation of fused five-membered rings by intramolecular cyclodehydration, often difficult to accomplish, was found to be smoothly effected in anhydrous HF, provided the reactivity index (N_t) for the appropriate electrophilic addition was favorable.The dihydro polycyclic aromatic alcohols obtained from reduction of the c orresponding keto cyclodehydration products were best dehydrated to the desired PAH by activity grade I neutral alumina in refluxing benzene.This dehydration proceeds in high yield without the formation of isomeric or polymeric side products that occurred even under such mild acid catalysis as p-toluenesulfonic acid.