Research Interests

The Stereoisomers of Organic Molecules
and the Rates of Intramolecular Processes

Scientific Aims

• Investigation of the separability of interconvertible stereoisomers at suitable temperatures.
• Determination and discussion of the steric structures; relative and absolute configurations.
• Measurement of the rates of thermal intramolecular processes, calculation of their activation parameters, their comparison, and their mechanistic discussion.

Selected publications: No. 1 - 17

Experimental Methods

• Synthesis of organic compounds forming interconvertible stereoisomers.
• Preparative separation of the isomers by crystallization or by enantioselective liquid chromatography using chiroptical detection.
• Stereoanalysis by means of polarimetry, circular dichroism, enantioselective ¹H-NMR spectroscopy and liquid chromatography.
• Kinetic measurement of isomerizations by polarimetric or ¹H-NMR methods.

Aspects of Teaching

• Diastereomeric association complexes are relevant for organic stereochemistry in the following fields: Separation of enantiomers via crystallization of diastereomers, analysis of enantiomers by NMR, separation of enantiomers by chromatography and reactivities of enantiomers in enzymatic resolution. It is proposed to introduce the common basis of these four aspects into teaching.
• Diastereomeric association complexes are also relevant for the activities of enantiomers via biological receptors, i.e. for the effects of chiral drug, pesticide and odorant molecules. It is proposed to introduce the common basis of these three fields into teaching.
• The herbicide metolachlor shows several stereoisomers with unequal biological activities and is produced by a large-scale enantioselective catalytic synthesis. These aspects of metolachlor may serve in teaching to illustrate a number of general aspects of stereochemistry.
• The enantiomers of odorant molecules, accompanied by brief information on their smells and their applications, are proposed as examples for introductory stereochemistry courses.
• Rose odorants and a few further fragrant molecules serve to present constitional isomers, enantiomers, and diastereomers.
• The structure of D-glucose can be taught via the Fischer projection or via x-ray diffractions.
• Possible role of medium-level review articles in chemistry.

Selected publications: No. 18 - 26