The syntheses of 1, 1′-, 9, 9′-, and 1, 9′-dianthryl-, 2, 2′-, 3, 3′-, and 9, 9′- diphenanthryl-, 1, 1′-and 2, 2′-dipyrenyl-, and 6, 6′-dichrysenylacetylenes according to the pyrolytic reactions of the corresponding β-ketoalkylidenetriphenylphosphorane derivatives (intramolecular Wittig reaction) were described.
