ERNEST L. ELIEL is W. R. Kenan, Jr. Professor Emeritus at the University of North Carolina at Chapel Hill. He is the author of Stereochemistry of Carbon Compounds and Elements of Stereochemistry, coeditor of the Wiley series, Topics in Stereochemistry, and coauthor of Conformational Analysis. The recipient of numerous academic and scientific awards and honors, Professor Eliel is Past President of the American Chemical Society and a member of the National Academy of Sciences. SAMUEL H. WILEN is Professor of Chemistry at City College, City University of New York, where he has taught since 1957. Professor Wilen is the author of Tables of Resolving Agents and Optical Resolutions, coauthor of Enantiomers, Racemates and Resolutions, and coeditor of the Wiley series, Topics in Stereochemistry. LEWIS N. MANDER has been Professor of Chemistry at the Australian National University since 1980. He has held visiting appointments at Cambridge University, California Institute of Technology, and Harvard University. His research interests are concerned with the development of methods and strategies for the synthesis of complex organic molecules with a special interest in plant growth and development.