“…Nitration of 5,13-di- tert -butyl-8,16-dimethoxy[2.2]MCP ( 1 ) with various nitrating agents led to an intramolecular condensation reaction at the intraannular 8,16-positions to give 5,13-di- tert -butyl-8,16-epoxy[2.2]MCP ( 4 ) in 5−12% yield along with ipso -nitration products 2 and 3 . The present novel intramolecular condensation reaction of two methoxy groups might be similar to the protic-acid catalyzed condensation of 2,2‘-dihydroxybiphenyls to afford dibenzofurans at high temperatures (above 200 °C) . Thus, attempted condensation of 1 to afford 4 in the presence of protic acids, such as sulfuric acid, trifluoroacetic acid, trifluoromethanesulfonic acid, and Lewis acids, such as titanium tetrachloride and aluminum chloride−nitromethane, under various conditions failed.…”