T. Yamato et al., A CONVENIENT PREPARATION OF ROMETHYL-2,7-DIMETHOXY-1,3,6,8-TETRAMETHYLFLUORENE USING FRIEDEL-CRAFTS INTRAMOLECULAR CYCLOBENZYLATION, Journal of chemical research. Synopses, (4), 1993, pp. 146-147
When chloromethylation of 4,4'-dimethoxy-3,3',5,5'-tetramethylbiphenyl
(1) was carried out under various conditions in order to prepare the
corresponding 2,2'-bis(chloromethyl) derivative (2), unexpected intram
olecular cyclobenzylation products, 2,7-dimethoxy-1,3,6,8-tetramethylf
luorene derivatives (4 and 5), were obtained along with thyl)-4,4'-dim
ethoxy-3,3',5,5'-tetramethylbiphenyl (3).