Related Experiment Video
Updated: Aug 9, 2026

Coulomb Explosion Imaging as a Tool to Distinguish Between Stereoisomers
Published on: August 18, 2017
An attempt to determine the absolute configuration of two ascolactone stereoisomers with time-dependent density
Simon F Seibert1, Gabriele M König, Elena Voloshina
1Institute for Pharmaceutical Biology, University of Bonn, Bonn, Germany.
Abstract:
Two stereoisomers of ascolactone (A, B), natural products with two asymmetric carbon atoms, are isolated from the marine-derived fungus Ascochyta salicorniae. Although these compounds show virtually opposite CD spectra and [alpha]D, 1H- and 13C-NMR data exclude the presence of enantiomers and suggest ascolactone A and B to be epimeric lactones. By comparing the experimental CD spectra with those calculated employing time-dependent density functional theory (TDDFT), we elucidate the configuration at one of the asymmetric carbon atoms.
More Related Videos
Related Concept Videos
Stereoisomerism of Cyclic Compounds
Prochirality
Stereoisomers
Stereoisomerism
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
Stability of Substituted Cyclohexanes
The two chair conformations of cyclohexanes undergo rapid interconversion at room temperature. Both forms have identical energies and stabilities, each comprising equal amounts of the equilibrium mixture. Replacing a hydrogen atom with a functional group makes the two conformations energetically non-equivalent.
For example, in...
Diels–Alder Reaction Forming Cyclic Products: Stereochemistry

