It war found by x-ray diffraction analysis that in the fulvenes studied, the aromatic rings of the condensed tricyclic fragment are not in the same plane. The angle between them is approximately 4°. The exocyclic carbon atom is at the same angle relative to the plane of the five-membered ring. Starting from 9-(4-pyridylmethylidene)fluorene, there were obtained 3-(4-pyridyl)spirooxirane[2,9′]fluorene and 1,2,3,4-trimethoxycarbonyl-8-(fluorylidene-9-methylene)-9a-H-quinolizine. ©1999 Kluwer Academic/Plenum Publishers.