The Stereochemistry of 1,2,3-Triols Revealed by 1 H NMR Spectroscopy: Principles and Applications (original) (raw)

The conformational compositions of the tris(a-methoxy-a-phenylacetic acid) ester derivatives of 1,2,3prim,sec,sec-triols are presented. These conformations have been determined by theoretical and experimental data (i.e., energy-and chemical-shift calculations, circular dichroism (CD) experiments, coupling-constant analysis, enantioselective deuteration experiments, and low-temperature NMR spectroscopic studies). A detailed analysis of the anisotropic effects due to the most significant conformers in the 1 H NMR spectra supported the correlation between the 1 H NMR spectra (Dd RS value of H(3') and j DA C H T U N G T R E N N U N G (Dd RS ) j parameters) and the absolute configuration of the substrate. The study also allows the identification of the pro-R and pro-S methylene protons from their vicinal coupling constants and relative chemical shifts.