https://doi.org/10.1351/goldbook.A00372
Originally the thermodynamic preference for polar groups bonded to C-1 (the anomeric carbon of a glycopyranosyl derivative) to take up an
This effect is now considered to be a special case of a general preference (the generalized anomeric effect) for
In alkyl glycopyranosides the anomeric effect operates at two sites (i) along the endocyclic C-1 oxygen bond (endo-anomeric effect) and (ii) along the exocyclic C-1 oxygen bond (![Not defined](/img/inline/A00372-3.png)
axial
position. ![Not defined](/img/inline/A00372-1.png)
synclinal
(gauche
) conformations about the bond C–Y in the system X–C–Y–C where X and Y are heteroatoms having nonbonding electron pairs, commonly at least one of which is nitrogen, oxygen or fluorine. For example in chloro(methoxy)methane the anomeric effect stabilizes the synclinal
conformation
. ![Not defined](/img/inline/A00372-2.png)
exo
-anomeric effect). The opposite preference is claimed for some systems, e.g., glycopyranosyltrialkylammonium salts, and has been referred to as the reverse anomeric effect. ![Not defined](/img/inline/A00372-3.png)