tricyclo[9.4.0.0^{3,8}]pentadeca-1(11),3,5,7,12,14-hexaen-2-one
tricyclo[9.4.0.0^{3,8}]pentadeca-1(15),3,5,7,11,13-hexaen-2-one
tricyclo[9.4.0.03,8]pentadeca-1(11),3(8),4,6,12,14-hexaen-2-one
tricyclo[9.4.0.03,8]pentadeca-1(15),3,5,7,11,13-hexaen-2-one