Novel Templating Effect in the Macrocyclization of Functionalized Diynes by Zirconocene Coupling This work was supported by the Director, Office of Basic Energy Sciences, Chemical Sciences Division, of the U.S. Department of Energy under Contract No. DE-AC03-76SF00098. The Center for New Directions in Organic Synthesis is supported by Bristol-Myers Squibb as Sponsoring Member. We also thank Dr. F. J. Hollander of the U.C. Berkeley X-ray diffraction facility (CHEXRAY) for help with determination of the X-ray structures.