Spatial Structure and Conformational Mobility of Seven-Membered Cyclic Acetals and Ketals Containing Pyridoxine Moiety in Solution by NMR Methods

In the last decade, pyridoxine derivatives were widely used for the synthesis of molecules with important biological and physical properties. However, rational synthesis of the compounds with desirable biochemical or physical properties often requires information about their spatial structure and conformational mobility. NMR spectroscopy is a powerful tool for conformational analysis of biologically important samples, such as pyridoxine derivatives, in solution. This paper is devoted to a review of the results obtained by our group over the last 5years on the NMR study of nine newly synthesized pyridoxine derivatives in acetone solution. It was shown that studied compounds are involved into several conformational exchange processes. The activation energies of all observed conformational exchange processes were calculated.