ABSTRACT
The absolute congurations (ACs) are most commonly determined using stereoselective chemical synthesis, X-ray crystallography, and/or nuclear magnetic resonance (NMR) spectroscopy. Stereoselective chemical syntheses require the knowledge of the ACs of the synthetic precursors and of the stereochemical course in the reaction pathway. The X-ray diffraction methods for determining the ACs require quality single crystals of the compounds (or their derivatives) being studied. The NMR methods for determining the ACs require chiral shift reagents and empirical correlations associated with interpreting the chemical shifts. Chiroptical spectroscopic methods are not limited by these requirements and the experimental measurements can be conducted for native chiral compounds in a liquid solution phase. Due to these distinct advantages, many nonspecialists were attracted, in recent years, to adopt the chiroptical spectroscopic methods for AC determinations. In practical terms, these methods are facilitated by the readily available instrumentation for experimental chiroptical spectroscopic measurements, and the computer algorithms for modern quantum chemical predictions of the corresponding properties.
