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An anomer is a type of stereoisomer and epimer found in carbohydrate chemistry. While an epimer is a stereoisomer that differs in configuration at any single stereogenic center, an anomer is a cyclic saccharide and an epimer that differs in its configuration, specifically at the hemiacetal/acetal carbon, also called the anomeric carbon. The anomeric carbon is the carbon derived from the carbonyl carbon (the ketone or aldehyde functional group) of the open-chain form of the carbohydrate molecule. Anomerization is the process of conversion of one anomer to the other. ==Nomenclature== Two anomers are designated alpha (α) or beta (β), according to the configurational relationship between the ''anomeric centre'' and the ''anomeric reference atom'', hence they are relative stereodescriptors. 〔IUPAC Gold Book (''α (alpha), β (beta)'' )〕 The anomeric centre in hemiacetals is the anomeric carbon C-1. In hemiketals it is the carbon derived from the carbonyl of the ketone (e.g. C-2 in D-fructose). In aldohexoses the anomeric reference atom is the stereocenter that is farthest from anomeric carbon in the ring (the configurational atom, defining the sugar as D or L). In α-D-glucopyranose the reference atom is C-5. If in the cyclic Fischer projection〔http://www.chem.qmul.ac.uk/iupac/2carb/05.html〕 the exocyclic oxygen atom at the anomeric centre is cis (on the same side) to the exocyclic oxygen attached to the anomeric reference atom (in the OH group) the anomer is α. If the two oxygens are trans (on different sides) the anomer is β.〔(Nomenclature of Carbohydrates (Recommendations 1996) ) (PDF )〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「anomer」の詳細全文を読む スポンサード リンク
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