A formal [4 + 2] dimerization of 9-cyclopropylidene-9H-fluorene
The methylenecyclopropanes 7 and 8, with aryl substituents fixed in a coplanar conformation, show an extraordinary readiness to dimerize with formation of 10 and 11, respectively. VCH Verlagsgesellschaft mbH, 1996.
Dyker, Gerald,Hillebrand, Gerhard,Ernst, Ludger,Dix, Ina,Jones, Peter G.