IN TOPICS STEREOCHEMISTRY VOLUME 14 ADVISORY BOARD STEPHEN J. ANGYAL, University of New South Wales, Sydney, Aus- tralia ALAN R. BATTERSBY, Cambridge University, Cambridge, England GIANCARLO BERTI, University of Pisa, Pisa, Italy F. ALBERT COTTON, Texas A&M University, College Station, Texas JOHANNES DALE, University of Oslo, Oslo, Norway DAVID GINSBURG, Technion, Israel Institute of Technology, Haifa, Israel JEAN-MARIE LEHN, Colidge de France, Paris, France JAN MICHALSKI, Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Lodz, Poland KURT MISLOW, Princeton University, Princeton, New Jersey SAN-ICHIRO MIZUSHIMA, Japan Academy, Tokyo, Japan VLADIMIR PRELOG, Eidgenossische Technische Hochschule, Zu- rich, Switzerland GUNTHER SNATZKE, Ruhruniversitat, Bochum, Federal Republic of Germany JOHN B. STOTHERS, University of Western Ontario, London, On- tario, Canada HANS WYNBERG, University of Groningen, Groningen, The Neth- erlands TOPICS IN STEREOCHEMISTRY EDITORS NORMAN L. ALLINGER Professor of Chemistry University of Georgia Athens, Georgia ERNEST L. ELIEL Professor of Chemistry University of North Carolina Chapel Hill, North Carolina SAMUEL H. WILEN Professor of Chemistry City College, City University of New York New York, New York VOLUME 14 AN INTERSCIENCE @ PUBLICATION JOHN WILEY 81 SONS - New York Chichester Brisbane Toronto Singapore * * * An Interscience" Publication Copyright 0 by John Wiley & Sons, Inc. 1983 All rights reserved. Published simultaneously in Canada. Reproduction or translation of any part of this work beyond that permitted by Section or the 107 I08 of United States Copyright Act without the permission 1976 of the copyright owner is unlawful. Requests for permission or further information should be addressed to the Permissions Department, John Wiley & Sons, Inc. Libmy of Congress Catalog Card Number: 67-13943 ISBN 0-471-89858-9 Printed in the United States of America 1 0 9 8 7 6 5 4 3 2 1 INTRODUCTION TO THE SERIES During the past two decades several texts in the areas of stereochemistry and conformational analysis have been published, including Stereochem- istry of Carbon Compounds (Eliel, McGraw-Hill, 1962) and Confor- inationul Analysis (Eliel, Allinger, Angyal, and Morrison, Interscience, 1965). While the writing of these books was stimulated by the high level of research activity in the area of stereochemistry, it has, in spurred turn, further activity. As a result, many of the details found in these texts are already inadequate or out of date, although the student in stereochemistry and conformational analysis may still learn the basic concepts of the subject from them. For both human and economic reasons, standard textbooks can be revised only at infrequent intervals. Yet the spate of periodical publica- tions in the field of stereochemistry is such that it is an almost hopeless for anyone to update himself by reading all the original literature. task The present series is designed to bridge the resulting gap. If that were its only purpose, this series would have been called “Ad- vances (or “Recent Advances”) in Stereochemistry.” It must be remem- bered, however, that the above-mentioned texts were themselves not treatises and did not aim at an exhaustive treatment of the field. Thus the present series has a second purpose, namely, to deal in greater detail with some of the topics summarized in the standard texts. It is for this reason that we have selected the title Topics in Stereochemistry. .The series is intended for the advanced student, the teacher, and the active researcher. A background for the basic knowledge in the field of stereochemistry is assumed. Each chapter is written by an expert in the field and, hopefully, covers its subject in depth. We have tried to choose topics of fundamental import aimed primarily at an audience of inorganic and organic chemists but involved frequently with fundamental principles of physical chemistry and molecular physics, and dealing also with certain stereochemical aspects of biochemistry. It is our intention to bring out future volumes at intervals of one to two years. The editors will welcome suggestions to suitable topics. as We are fortunate in having been able to secure the help of an inter- national of editorial advisers who have been of great assistance by board suggesting topics and authors for several chapters and by helping us avoid V vi INTRODUCTION TO THE SERIES duplication of topics appearing in other, related monograph series. We are grateful to the editorial advisers for this assistance, but the editors and authors alone must assume the responsibility for any shortcomings of Topics in Stereochemistiy . N. L. ALLINGER E. L. ELIEL S. H. WILEN PREFACE In the first of four chapters in this volume of Topics in Stereochem- istry, Michinori Oki presents a comprehensive review of atropisomerism with special reference to the literature of the P ast two decades. The review summarizes restricted rotation about sp2-sp , sp2-sp3,a nd sp3-sp3 bonds and it concludes with an analysis of reactions of isolated rotational iso- mers. It places particular emphasis on the magnitude of rotation barriers as a function of structure (incidentally identifying some of the largest barriers yet measured to conformer interconversion) and on the isolation of stable single-bond rotational diastereomers. The second chapter, by Jan Sandstrom, deals with stereochemical features of “push-pull” ethylenes. The focus is on rotational barriers, which span a large range of values. The ease of twisting is partly a matter of electron delocalization and partly a matter of steric and solvent effects. Electronic structure and such related items as dipole moments and pho- toelectron spectra for these systems are discussed. The chapter also deals with the structure and chiroptical properties of twisted ethylenes that do not have push-pull effects, such as trans-cyclooctene. In the third chapter, Hans Hirschmann and Kenneth R. Hanson provide a detailed analysis of the principles of stereochemical classification or factorization. In contrast to the system earlier proposed by Cahn, Ingold, and Prelog (and recently extended and modified by Prelog and Helmchen) featuring centers, axes, and planes of chirality, Hirschmann and Hanson here present an alternative scheme not limited to chiral structures. This scheme for the factorization of stereoisomerism uses as principal elements the center and line of stereoisomerism. Numerous examples are given. In the fourth and final chapter, Howard Haubenstock discusses asym- metric reduction of organic molecules. Within this general topic of wide and continuing interest, Haubenstock’s chapter deals with chiral deriv- atives of lithium aluminum hydride, their preparation from suitable amino or hydroxy compounds, and their use in reducing carbonyl groups. Re- lated reactions of the Meerwein-Ponndorf-Verley type or involving ti- alkylaluminum reagents are also presented. Professor Guy Ourisson, who served as one of our editorial advisors since the beginnings of Topics of Stereochemistry some 15 years ago, has now relinquished his position; we are grateful to him for his valuable vii viii PREFACE advice over the years. In turn, we welcome two new members to our Editorial Advisory Board: Professor Jean-Marie Lehn (Collbge de France, and Professor John Stothers (University of Western Ontario, Paris) B. London, Ontario, Canada) who will help us maintain-and even ex- tend-the world-wide representation of our advisors. NORMAN L. ALLINGER ELIEL ERNEST L. SAMUEL H. WILEN Athens, Georgia Chapel Hill, North Carolina New York, New York January 1983 CONTENTS RECENT ADVANCES IN ATROPISOMERISM 1 by Michinori Oki, Department of Chemistry, Faculty of Science, The University of Tokyo, Tokyo, Japan STATIC AND DYNAMIC STEREOCHEMISTRY OF PUSH-PULL AND STRAINED ETHYLENES 83 by Jan Sandstrom, Division of Organic Chemistry 3, Chemical Center, University of Lund, Lund, Sweden ON FACTORING CHIRALITY AND STEREOISOMERISM 183 by Hans Hirschmann, Department of Medicine, Case Western Reserve University, Cleveland, Ohio; and Kenneth R. Hanson, Department of Biochemistry and Genetics, The Connecticut Agricultural Experiment Station, New Haven, Connecticut ASYMMETRIC REDUCTIONS WITH CHIRAL COMPLEX ALUMINUM HYDRIDES AND TRICOORDINATE ALUMINUM REAGENTS 231 by Howard Haubenstock, Department of Chemistry, The City University of New York, The College of Staten Island, Staten Island, New York. SUBJECT INDEX 301 CUMULATIVE INDEX, VOLUMES 1-14 311 ix TOPICS IN STEREOCHEMISTRY VOLUME 14