The anomalous axial preference of electronegative substituents at the anomeric center C(1) of the pyranose ring was first noted by Edward in 1955 and was clearly defined as the anomeric effect by Lemieux and Chü, which plays a defining role in molecular conformation and reactivity, and is now recognized as one of the most important stereo-electronic effect in organic chemistry. The anomeric effect is recognized in an Lp-X-A-Y moiety as a preference for an antiperiplanar arrangement of the lone pair (Lp) and the A—Y bond, where X is a heteroatom, A is an element with intermediate electronegativity, and Y is a group with higher electronegativity (such as oxygen, nitrogen, fluorine, etc.). In this paper, the anomeric effect, general-ized anomeric effect, reverse anomeric effect, endo-anomeric effect and exo-anomeric effect are described. The potential application of the anomeric effect is supplied.

Key words: generalized anomeric effect, anomeric effect, reverse anomeric effect, hydrogen bond