1. Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, ExxonMobil Research and Engineering Company, Corporate Strategic Research Laboratory, 1545 Route 22 East, Clinton Township, Annandale, New Jersey 08801-3059, and Reilly Industries, Inc., 1500 South Tibbs Avenue, P.O. Box 42912, Indianapolis, Indiana 46242