Quantitative analysis for enantiomeric purity of alkan-2-ols by fluorine-19 magnetic resonance spectroscopy

Abstract

Fluorine magnetic resonance spectroscopy has been investigated as a means of determining the enantiomeric purity of alkan-2-ols. These were converted into the l-mandelate diastereomers, which were allowed to react with trifluoroacetic anhydride. The fluorine magnetic resonance spectrum of the trifluoroacetyl derivatives shows a pair of signals, and the relative signal heights of a resonance pair were compared to permit the quantitative determination of the proportions of the components in the enantiomeric mixture. Agreement between the results given by the nuclear magnetic resonance method and gas chromatography was satisfactory.