Application of coupling constant based analysis in determining the relative configuration of flexible natural molecules
The determination of the relative configuration of fiexible natural molecules is still a challenge due to the geometrical uncertainty of their flexible moieties. Coupling constant based configuration analysis(JBCA) is a valid approach in elucidating the relative configuration of these flexible systems. The approach is suitable for 1,2- or 1,3-dimethine systems. The final relative configuration assignment on chiral organic compounds stems from conformational analysis by combining proton-proton and/or proton-carbon coupling values and nuclear overhauser effect(NOE) correlations. This paper gives a brief review on the latest application of coupling constant based analysis in determining the relative configuration of flexible natural molecules,aiming to give a reference to natural product research regarding the stereochemistry.