1H NMR determination of absolute configuration of 1- or 2-aryl-substituted alcohols and amines by means of their diastereomers: novel separation technique of diastereomeric derivatives of pyridyl alcohols by extraction

A convenient method to determine the absolute configuration of trans-2-aryl cyclohexanols, 1-aryl alcohols and amines was achieved. This method takes advantage of the 1H NMR spectroscopic observations of the remarkable high-field shift of C18-CH3 protons caused by the aromatic shielding effect. It is based on a discrimination of the difference of the environments in two diastereomers derived from 3 beta-acetoxy-5-etienic acid. Furthermore, it was observed that the corresponding diastereomeric derivatives of the pyridyl alcohols were simply separated by extraction based on the difference in their basicity.