出典:Wikipedia
出典:『Wikipedia』 (2011/01/24 18:49 UTC 版)
In organic chemistry, the anomeric effect or Edward-Lemieux effect is a stereoelectronic effect that describes the tendency of heteroatomic substituents adjacent to a heteroatom within a cyclohexane ring to prefer the axial orientation instead of the less hindered equatorial orientation that would be expected from steric considerations. This effect was originally observed in pyranose rings by J. T. Edward in 1955; at that time, N.-J. Chii and R. U. Lemieux began to study the anomerization equilibria of the fully acetylated derivatives of several aldohexopyranoses. The term "anomeric effect" was introduced in 1958. The anomeric effect got its name from the term used to designate the C-1 carbon of a pyranose, the anomeric carbon. Isomers that differ only in the configuration at the anomeric carbon are called anomers.