Formation of fluorene and anthracene derivatives in reactions of perfluorinated 1-alkyl-1-phenyl- and 1-alkyl-2-phenyl-1,2-dihydrocylobutabenzenes with antimony pentafluoride

The reaction of perfluoro(1-methyl-1-phenyl-1,2-dihydrocyclobutabenzene) with SbF₅ at 50°C, followed by hydrolysis, gave perfluoro(1-phenylindan-1-ol), while analogous reaction at 90°C afforded perfluoro10-methylanthracen-9(10H)-one]. Perfluoro(1-methyl-2-phenyl-1,2-dihydrocyclobutabenzene) did not undergo skeletal transformations under analogous conditions, whereas at 200°C it was converted mainly into perfluoro(9-methylfluoren-9-ol). Perfluoro(1-ethyl-2-phenyl-1,2-dihydrocyclobutabenzene) reacted with SbF5 at 200°C to form perfluoro(9-ethylfluoren-9-ol) together with perfluorinated 9,9-dimethyl- and 9-ethyl-9-methyl-1,2,3,4-tetrahydro-9H-fluorenes.