ADDITION AND CYCLIZATION REACTIONS IN THE THERMAL CONVERSION OF HYDROCARBONS WITH AN ENYNE STRUCTURE, 4 - FORMATION AND REARRANGEMENTS OF BICYCLIC C10H8 AROMATICS FROM 1-PHENYL-1-BUTEN-3-YNE

The thermal conversion of 1-phenyl-1-buten-3-yne (1) into the cycloiso merization products naphthalene (2), azulene (3), and 1-methylene-1H-i ndene (4) has been studied at temperatures between 550 and 1000 degree s C, a reaction time of approximately 0.3 s at 13 Torr (FVP) and at lo w partial pressures in a quartz flow system. The results obtained by F VP as well as in the presence of chemically modified diluent gases sug gest a predominance of unimolecular cycloisomerizations to 2 and 3 whi ch are, however, always accompanied by radical cyclization reactions t o 2 and 4 even under FVP conditions if temperatures above 550 degrees C are applied.