Absolute Configuration Determination of Sugar: A Review of the Different Methods

Determination of the stereochemistry of the stereocenter from the aglyconic part of carbohydrates is always one of the most important tasks for chemistry carbohydrates researchers. The absolute configuration (AC), a challenge for synthetic chemists, has attracted much attention. During the past few decades, many techniques and approaches have been developed to determine the AC of carbohydrates, including methods of X-ray diffraction (XRD), electronic and vibrational circular dichroism (ECD and VCD), Raman optical activity (ROA), nuclear magnetic resonance (NMR) utilizing anisotropic effects of chiral derivatizing agents, and quantum chemical calculations. On the other hand, none of the currently applied techniques can dominate AC determination, since they each have their respective limitations corresponding to the different structural features. This review summarizes most of the techniques and methods commonly used in AC assignment of carbohydrates (but specifically glycosides), in the last decades (2000-2023). GRAPHICAL ABSTRACT