Fluoro-substitution effects in deoxyfluoro-D-glucose derivatives:random conformational search and quantum chemical calculation

摘要

The effect of substitution by the fluorine atom at different positions of D-glucose was investigated by quantum chemical calculation of the low-energy conformers.These were obtained through the Random conformational search method.The geometries of conformers were optimized at the RHF/6-31(d) level,then reoptimization and vibrational analysis were performed at the B3LYP/ 6-31+G(d) level.Single-point energies were calculated at the B3LYP/6-311++G(2d,2p) level.The free energies of solvation in water were calculated utilizing the AM1-SM5.4 solvation model.For all substitution positions,the ring conformation does not change much,and the pyranoid ~4C_1 conformers are dominant,while variations in the substitution site result in different effects in the network of hydrogen bonds,anomeric effect,the solvation free energy,and the ratio of alpha-and beta-anomers.