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The Stereochemistry of 1,2,3‐Triols Revealed by 1 H NMR Spectroscopy: Principles and Applications
Author(s) -
Freire Félix,
Lallana Enrique,
Quiñoá Emilio,
Riguera Ricardo
Publication year - 2009
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200901505
Subject(s) - conformational isomerism , chemistry , coupling constant , chemical shift , nmr spectra database , vicinal , methylene , nuclear magnetic resonance spectroscopy , spectral line , crystallography , spectroscopy , substrate (aquarium) , carbon 13 nmr satellite , circular dichroism , two dimensional nuclear magnetic resonance spectroscopy , stereochemistry , fluorine 19 nmr , molecule , organic chemistry , physics , oceanography , particle physics , quantum mechanics , astronomy , geology
The conformational compositions of the tris(α‐methoxy‐α‐phenylacetic acid) ester derivatives of 1,2,3‐ prim , 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 (Δ δ RS value of H(3′) and |Δ(Δ δ RS )| 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.