A general synthetic strategy and biological activity of B -Phytoprostanes 1 Dissertation zur Erlangung des akademischen Grades doctor rerum naturalium (Dr. rer. nat.) vorgelegt dem Rat der Chemisch-Geowissenschaftlichen Fakultät der Friedrich-Schiller-Universität Jena von Diplomchemikerin Annika Schmidt geboren am 11. September 1979 in Greiz Gutachter: 1. Prof. Dr. Wilhelm Boland Max-Planck-Institut für Chemische Ökologie Jena; Abteilung Bioorganische Chemie 2. Prof. Dr. Dieter Klemm Institut für Organische und Makromolekulare Chemie; Friedrich-Schiller-Universität Jena Tag der öffentlichen Verteidigung: 18.04.2007 Table of contents III 1 Introduction 1-14 1.1 Plant defence reactions 1 1.2 Phytohormones as regulators of plant development and defence 3 1.3 Phytoprostanes and dinor isoprostanes 8 1.3.1 Occurrence, biosynthesis and diversity of phytoprostanes 8 1.3.2 Biological importance of B-phytoprostanes 10 11.3.3 Relationship between prostaglandins, isoprostanes and phytoprostanes 12 2 Objectives for this work 15-16 3 Results and discussion 17-61 3.1 Synthetic strategies 17 3.1.1 Previously published phytoprostane syntheses 3.1.2 Synthetic concepts 20 3.1.2.1 Attachment of the C2-substituent to the five-membered ring 22 3.1.2.2 Attachment of the C3-subs26 3.1.2.