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Within the present project several new aspects of determination of absolute configurations will be studied. Determination of absolute configurations of vicinal secondary diols is good starting point for the studies of many polyfunctional natural and synthetic chiral compounds, from them sugars are most important group of compounds. Esterification of vicinal secondary diol with the two sterically crowded MPA residues must result in some diesters in remarkable deviations from the preferred conformation, where the carbinol proton and oxygen atoms of MPA residue are on the same plane. Conformational equilibrium will be studied by molecular mechanics (MMFF94) and semiempirical quantum chemistry (AM1) calculations. Hopefully these calculations result in the explanation of deviations of additivity of anisotropy effects.The use of cyclodextrins for the differentiation of enantiomers does not need the derivatization of target chiral molecules. Comparison on published results about the differences in equilibrium constants of cyclodextrin complexation reactions of enantiomers by different methods reveals, that nearly in all cases the reported differences are within the limits of errors of used methods. Within the present project the potential of high field NMR spectroscopy on this topic will be studied. Starting point in this is our NMR methodology for the determination of very small differences in the acid-base dissociation constants of organic compounds. The use of chiral liquid crystal solvents for the differentiation of enantiomers will be investigated. NMR spectroscopy will be used within the project for the studies of equilibria, kinetics and dynamics of enzymatic reactions. Tautomeric amino-imino equilibrium and its thermodynamics in 2-aminosubstituted pyridine derivatives will be studied. NMR spectroscopy will be used for the analysis of specifcally prepared outer heterogeneous layers of dendrimeric molecules. In the field of macromolecules polysaccharides from the Baltic Sea algae and humic substances from the Estonian curative muds will be under the high field NMR studies. |