Organic Mechanisms Reactions, Stereochemistry and Synthesis Reinhard Bruckner Organic Mechanisms Reactions, Stereochemistry and Synthesis Edited by Michael Harmata With a foreword by Paul A. Wender Prof. Dr. Reinhard Bruckner Albert-Ludwigs-Universität Freiburg Institut für Organische Chemie und Biochemie Albertstr. 21 79104 Freiburg [email protected] Prof. Dr. Michael Harmata Norman Rabjohn Distinguished Professor of Chemistry Department of Chemistry University of Missouri-Columbia 601 S. College Avenue Columbia, Missouri 65211 [email protected] Translation: Karin Beifuss ISBN: 978-3-642-03650-7 e-ISBN: 978-3-642-03651-4 DOI: 10.1007/978-3-642-03651-4 Library of Congress Control Number: 2009938642 © Springer-Verlag Berlin Heidelberg 2010 Translation of Brückner, R Reaktionsmechanismen, 3rd edition, published by Spektrum Akademi- scher Verlag, © 2007 Spektrum Akademischer Verlag, ISBN 987-3-8274-1579-0 This work is subject to copyright. 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Cover design: KuenkelLopka GmbH Printed on acid-free paper 987654321 springer.com Biographies Reinhard Bruckner (born 1955) studied chemistry at the Lud- wig-Maximilians-Universität München, acquiring his doctoral degree under the supervision of Rolf Huisgen. After postdoctoral studies with Paul A. Wender (Stanford University), he completed his habilitation in collaboration with Reinhard Hoffmann (Philipps-Universität Marburg). He was appointed associate pro- fessor at the Julius-Maximilians-Universität Würzburg and full professor at the Georg-August-Universität Göttingen before he moved to his current position in 1998 (Albert-Ludwigs- Universität Freiburg). Professor Bruckner´s research interests are the total synthesis of natural products and the development of synthetic methodology. Besides being the author of 150 publications he has written 4 textbooks, for one of which he was awarded the Literature Prize of the Foundation of the German Chemical Industry. He has been a Visiting Professor in the US, Spain, and Japan, and served as an elected peer reviewer of the German Research Foundation and as the Vice-President of the Division of Organic Chemistry of the German Chemical Society. Michael Harmata was born in Chicago on September 22, 1959. He obtained his A.B. in chemistry from the University of Illinois- Chicago in 1980. He received a Ph.D. from the University of Illi- nois-Champaign/Urbana working with Scott E. Denmark on the carbanion-accelerated Claisen rearrangement. He was an NIH postdoctoral fellow in the labs of Paul A. Wender at Stanford Uni- versity, where he focused on synthetic work involving the neo- carzinostatin chromophore. He joined the faculty at the Univer- sity of Missouri-Columbia in 1986 and is now the Norman Rabjohn Distinguished Professor of Chemistry at that institution. Professor Harmata’s research interests span a large range of chemistry and include molecular tweezers, [4+3]-cycloadditions, pericyclic reactions of cyclopentadienones and benzothia zine chemistry. He enjoys cooking, reading, stamp collecting, and recently earned his black belt in Taekwondo. I dedicate this book to my family, who serve to support me in my pursuit of science and provide the love that so enriches my life. Judy L. Snyder Gail Harmata Diana Harmata Alexander Harmata Foreword “Much of life can be understood in rational terms if expressed in the language of chemistry. It is an international language, a language without dialects, a language for all time, a language that explains where we came from, what we are, and where the physical world will allow us to go. Chemical Language has great esthetic beauty and links the physical sciences to the bio- logical sciences.” from The Two Cultures: Chemistry and Biology by Arthur Kornberg (Nobel Prize in Physiology and Medicine, 1959) Over the past two centuries, chemistry has evolved from a relatively pure disciplinary pursuit to a position of central importance in the physical and life sciences. More generally, it has pro- vided the language and methodology that has unified, integrated and, indeed, molecularized the sciences, shaping our understanding of the molecular world and in so doing the direction, development and destiny of scientific research. The “language of chemistry” referred to by my former Stanford colleague is made up of atoms and bonds and their interactions. It is a sys- tem of knowledge that allows us to understand structure and events at a molecular level and increasingly to use that understanding to create new knowledge and beneficial change. The words on this page, for example, are detected by the eye in a series of events, now generally understood at the molecular level. This knowledge of molecular mechanism (photons in, elec- trons out) in turn enables us to design and synthesize functional mimetics, providing for the development of remarkable retinal prosthetics for those with impaired vision and, without a great leap in imagination, solar energy conversion devices. Similarly, the arrangement of atoms in natural antibiotics provides the basis for understanding how they function, which in turn has enabled the design and synthesis of new antibiotics that have saved the lives of count- less individuals. We are even starting to learn about the chemistry of cognition, knowledge that defines not only “what we are” but how we think. We have entered the age of molecular- ization, a time of grand opportunities as we try to understand the molecular basis of all science from medicine to computers, from our ancient past (molecular paleontology) to our molecu- lar future. From our environment and climate to new energy sources and nanotechnology, chemistry is the key to future understanding and innovation. This book is a continuation of a highly significant educational endeavor started by Rein- hard Bruckner and joined by Michael Harmata. It is directed at understanding the “language of chemistry”: more specifically, the structures of organic compounds; how structure influ- ences function, reactivity and change; and how this knowledge can be used to design and syn- thesize new structures. The book provides a cornerstone for understanding basic reactions in chemistry and by extension the chemical basis for structure, function and change in the whole of science. It is a gateway to the future of the field and all fields dependent on a molecular view for innovative advancement. In an age of instant access to information, Bruckner and Harmata provide special value in their scholarly treatment by “connecting the dots” in a way that converts a vast body of chemical information into understanding and understanding into knowledge. The logical and rigorous exposition of many of the core reactions and concepts of chemistry and the addition of new ones, integration of theory with experiment, the infusion of x Foreword “thought” experiments, the in -depth attention to mechanism, and the emphasis on fundamen- tal principles rather than collections of facts are some of the many highlights that elevate this new text. As one who has been associated with the education of both the author and the edi- tor, I find this book to be an impressively broad, deep and clear treatment of a subject of great importance. Students who seek to understand organic chemistry and to use that understand- ing to create transformative change will be well served in reading, studying and assimilating the conceptual content of this book. It truly offers passage to an exciting career and expertise of critical importance to our global future. Whether one seeks to understand Nature or to create new medicines and materials, Bruckner and Harmata provide a wonderfully rich and exciting analysis that students at all levels will find beneficial. Congratulations to them on this achievement and to those embarking upon this journey through the molecular world! October, 2009 Paul A. Wender Stanford University Preface to the English Edition This book is an attempt to amalgamate physical, mechanistic and synthetic organic chemistry. It is written by a synthetic organic chemist who happens to also think deeply about mecha- nism and understands the importance of knowing structure and reactivity to synthetic organic chemistry. I helped get the 1st German edition of this book translated into English, for two reasons. First, Reinhard Bruckner has been a friend of mine for over twenty years, ever since we were postdocs in the Wender group in the mid-80s. He was a study in Teutonic determina- tion and efficiency, and I, and a few other Americans, and one Frenchman in particular, have been trying to cure him of that, with some success, I might add, though he remains an extremely dedicated and hard-working educator and scientist. That’s a good thing. Second, I especially liked the project because I liked the book, and I thought Reinhard’s way of dealing with synthesis and mechanism together was an approach sufficiently different that it might be the “whack on the side of the head” that could be useful in generating new thought patterns in students of organic chemistry. Well, I was actually a bit surprised to be invited to work on the English translation of the 3rd German edition of the book. I was even more surprised when the publisher gave me edi- torial license, meaning I could actually remove and add things to the work.