COPLANAR AND STABLE DERIVATIVES OF 13,14-DIDEHYDRO-TRIBENZO[A,C,E]CYCLOOCTENE - SYNTHESIS OF 5,6-DIDEHYDRO-1,1,14,14-TETRAMETHYL-10,11-METHANO-1H-BENZO[5,6]CYCLOOCTA[1,2,3,4-DEF]FLUORENE AND 5,6-DIDEHYDRO-10,11-METHANO-1H-BENZO[5,6]CYCLOOCTA[1,2,3,4-DEF]FLUORENE-1,14-DIONE AND X-RAY CRYSTAL-STRUCTURES OF 1,1,14,14-TETRAMETHYL-10,11-METHANO-1H-BENZO[5,6]CYCLOOCTA[1,2,3,4-DEF]-FLUORENE AND 1,12-DIHYDRO-1,1,12,12-TETRAMETHYLDICYCLOPENTA[DEF,JKL]TETRAPHENYLENE
Wang, XM; Hou, XL; Zhou, ZY; Mak, TCW; Wong, HNC