2, 8, 17-Trithia [45, 12][9] metacyclophan-4-ene, a cyclophane with a tertiary olefin strapped across the face of a benzene ring, has been prepared and its X-ray structure determined. The olefin is pyramidalized toward the benzene ring. The X-ray structure of the corresponding saturated phane (in-2, 8, 17-trithia [45, 12][9] metacyclophane, which was synthesized previously) has also been determined. The structure and reactivity of the in- ...