(13)C CP MAS NMR and DFT Studies of 6-Chromanyl Ethereal Derivatives †

Vitamin E consists of a group of compounds including α- β- γ- and δ-tocopherols and α- β- γ- and δ-tocotrienols, containing the chroman-6-ol system. The recognition of the structural and dynamic properties of this system, present in all vitamers, seems to be important for the full explanation of the mechanism of the biological activity of vitamin E. This paper presents results of the structural analysis of the chosen 6-chromanyl ethereal derivatives using experimental ((13) C NMR-in solution and solid state, as well as variable temperature experiments; single crystal X-ray diffraction) and theoretical (DFT) methods. For one of the studied compounds, 2,2,5,7,8-pentamethyl-6-((tetrahydro-2H-pyran-2-yl)oxy) chroman, the splitting of some signals was observed in the (13)C dynamic NMR spectra. This observation was explained by the application of a conformational analysis and subsequent DFT optimization, followed by the calculation of NMR properties.