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Anomer

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	Topics Anomer Topic Home In sugarSugar In general use, non-scientists take "sugar" to mean sucrose, also called "table sugar" or saccharose, a white crystalline solid di... chemistryChemistry Chemistry is the science of matter at the atomic to molecular scale, dealing primarily with collections of atoms .... , an anomer is a special type of epimerEpimer In chemistry, an epimer is a stereoisomer of another compound that has a different configuration at only one of several chir... . It is a stereoisomer of a saccharideSaccharide Saccharide can have different meanings depending on the context:... (in the cyclic form) that differs only in its configuration at the hemiacetalFacts About Hemiacetal A hemiacetal is a functional group or compound containing the function group in the form of:... (or hemiketal) carbon, also called the anomeric carbon. If the structure is analogous to one with the hydroxyl group on the anomeric carbon in the axial positionCyclohexane conformation Overview Cyclohexane conformation is a much studied topic in organic chemistry because of the complex interrelationship between the d... of glucose, then the sugar is an alpha anomer. If, however, that hydroxyl is in the equatorialEquatorial Equatorial has different meanings:* In geography it relates to the equator of the earth.... position, then the sugar is a beta anomer. For example, a-D-glucopyranose and ß-D-glucopyranose, the two cyclic forms of glucoseGlucose Glucose , a monosaccharide , is one of the most important carbohydrates in biology.... , are anomers. For -L- the a and ß are contrarywise. (see Glycosidic bondGlycosidic bond Overview In chemistry, a glycosidic bond is a certain type of functional group that joins a carbohydrate molecule to an alcohol, whic... for details) The anomeric effectAnomeric effect In organic chemistry, the anomeric effect is the tendency of heteroatomic substituents next to a heteroatom in a cyclohexane... helps stabilize the a-anomer. The term for interconversion between the two anomers is mutarotationMutarotation Mutarotation is the term given to the change in the specific rotation of plane polarised light, when it is passed through an... . The two different anomers are two distinct chemical structures, and thus have different physical and chemical properties, notably optical rotationOptical rotation Optical rotation or optical activity is the rotation of linearly polarized light as it travels through certain materia... . For example, a-D-glucoseGlucose Glucose , a monosaccharide , is one of the most important carbohydrates in biology.... has an optical rotation of +112 degrees and its anomer, ß-D-glucose, has an optical rotation of +19 degrees. See also AnomerizationAnomerization Anomerization is the interconversion between the alpha and beta anomers of a carbohydrate.... Haworth projectionFacts About Haworth projection A Haworth projection is a common way of representing the cyclic structure of monosaccharides with a simple three-dimensional... External links On the Assignment of Anomeric Configuration (pdf)