Nuclear Magnetic Resonance Determination of Enantiomeric Composition and Absolute Configuration of Amines, Alcohols, and Thiols with α-acetic Acid as a Chiral Derivatizing Agent.

Article abstract of DOI:10.1021/jo00329a019

(R)-<1-(9-Anthryl)-2,2,2-trifluoroethoxy>acetic acid, easily prepared from commercially available (R)-2,2,2-trifluoro-1-(9-anthryl)ethanol, is a useful chiral reagent for the conversion of enantiomeric alcohols, thiols, or amines into diastereomeric derivatives.The resultant diasteremers typically have nonidentical NMR spectra, thus enabling NMR determination of the diastereomeric ratio, a ratio which reflects the original enantiomeric purity of the alcohol, thiol, or amine.A discussion of the conformational behavior of these derivatives is presented as is a conformational model for obtaining absolute configurations of the alcohol, thiol, or amine from the senses of the chemical shift differences noted between the diastereomeric derivatives.