2,5-dibenzylidene cyclopentanone 生成 1,4,8,10-Tetrakis-[1-phenyl-meth-(E)-ylidene]-6-oxa-spiro[4.6]undecan-9-one 、 (5R,6R,11R,12R)-11,12-Diphenyl-2,8-bis-[1-phenyl-meth-(E)-ylidene]-dispiro[4.0.4.2]dodecane-1,7-dione 、
6,12-Diphenyl-2,9-bis-[1-phenyl-meth-(E)-ylidene]-dispiro[4.1.4.1]dodecane-1,8-dione