The assignment of absolute configuration by NMR

Different approaches for determining the problem of absolute configuration based on nuclear magnetic resonance (NMR) spectroscopy were studied. The first approach involves those procedures where derivatization of the substrate whose absolute configuration was studied was not necessary. A pure enantiomer was analyzed by NMR in a chiral environment, provided by a chiral solvent or by the addition of a chiral solvating agent (CSA) to a nonchiral standard NMR solvent. Several instrumental methods for the determination of absolute configuration which include X-ray crystallography, chiro-optical methods, optical rotatory dispersion (ORD) or specific optical rotation were also described.