Outline of Contents
- Introduction
Definitions
Conformational isomers - Stereogenic centres
Configurational isomerism and chirality
Identifying stereoisomers - Stereogenic axes
Achiral molecules with chiral centres
Allenes, biaryls and helicenes - Enantiomers
Central chirality at atoms other than carbon
Properties of enantiomers - Diastereoisomers
Defining features of diastereoisomers
Relationships between atoms (or groups) within a molecule - Separation of enantiomers
Resolution via salt formation or derivatisation
Kinetic resolution - Analysis of enantiomers
Enantiomeric purity and the enantiomeric excess (e.e.) scale - Stereoselective reactions
Stereospecific and stereoselective reactions
The mechanistic basis of stereoselectivity
Generating stereogenic centres with achiral or chiral substrates
Recommended Reading and Support
- J. Clayden, N. Greeves and S. Warren, Organic Chemistry 2nd edition (Oxford University Press, 2012) ISBN 0199270295 (with useful extra chapters).
- M. J. T. Robinson, Organic Stereochemistry (Oxford Chemistry Primer, no. 88) (Oxford University Press, 2000) ISBN 0198792751 (affordable, technically thorough guidebook).
- E. L. Eliel and S. H. Wilen, Stereochemistry in Organic Compounds (Wiley, 1994) ISBN 0471016705 (a comprehensive reference text).
- Access to a set of molecular models (e.g. Orbit by Cochranes of Oxford) is invaluable.
Exercises
A series of exercises to accompany each of the eight topics can be downloaded using this link (PDF, opens in new window).
Background and Acknowledgements
The aim of this course is to foster an understanding of the key stereochemical relationships (enantiomeric, diastereoisomeric, configurational, conformational) in compounds with stereogenic centres and/or axes. The analysis extends to the mechanistic principles of stereoselectivity in synthetic reactions. Interactive molecular models are included so that structures can be explored in depth. The modelling software used is the JSmol molecular viewer.
The original version of this site supported a UG chemistry unit entitled Structural Relationships in Organic Chemistry, provided for Level 2 MChem students in the School of Chemistry of the University of Manchester. The web files were revised to improve their device compatibility and visual quality, and once again I thank Stuart Anderson for providing the template which made this task straightforward. This revision was completed during the COVID-19 lockdowns of 2020-2021.
Tim Wallace
Manchester, April 2021