Conformational study of anomeric center in some carbohydrate derivatives

Density functional theory (DFT) using the B3LYP functional and the split-valance 6-311++G** basis sets have been used to investigate the structures of 24 derivatives of glucose and galactose which present sequences of atoms in anomeric configurations of the C-C bond in C-glycosides, C-O bond in glycosides, C-S bond in thioglycosides, C-N bond in glycosylamines, and C-F/Cl bond in glycosyl halides. Values of the vicinal coupling constants, 3JCXCH (X = C, O, S), for mentioned compounds were calculated in water and methanol solvents by using PCM method and new Karplus equations were derived.