1. Institut für Organische Chemie, Universität Regensburg, Universitätsstrasse 31, D-93051 Regensburg, Germany, Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, Arany Janos Street No. 11, Cluj_Napoca 3400, Romania, Institute of Chemistry, Johannes Keppler University, Altenbergerstrasse 69, A-4040 Linz, Austria, Department of Chemistry, Princeton University, Washington Road, Princeton, New Jersey 08544-1009, and Institut für Botanik, Universität Regensburg, Universitätsstrasse 31, D...