title: Synthesis of cyclo-1,3-dien-5-ynes.
abstract: Cyclo-1,3-dien-5-ynes with ring sizes from 10 to 14 (6a-e) have been prepared for the first time by using a five-step synthesis starting from the alkynols 7a-e. The final ring-closure was achieved by McMurry coupling of the alpha,omega-dialdehydes 12a-e with the complex TiCl3(DME)1.5. Thermal isomerization of the cyclodienynes leads to the corresponding benzocycloalkenes, and it has been shown that the ring size has a considerable influence on the temperature necessary for thermocylization.
authors.affiliation: Institut für Organische Chemie, Technische Universität Braunschweig Braunschweig, Germany. h.hopf@tu-bs.de
authors.forename: H
authors.initials: H
authors.lastname: Hopf
authors.forename: A
authors.initials: A
authors.lastname: Krüger