Meso-2,3-Dihydroxybutanedioic acid

Metal meso-2, 3-Dihydroxybutanedioic acid (meso-tartaric acid) H.L... 

Tartaric acid [526-83-0] (2,3-dihydroxybutanedioic acid, 2,3-dihydroxysuccinic acid), C H O, is a dihydroxy dicarboxyhc acid with two chiral centers. It exists as the dextro- and levorotatory acid the meso form (which is inactive owing to internal compensation), and the racemic mixture (which is commonly known as racemic acid). The commercial product in the United States is the natural, dextrorotatory form, (R-R, R )-tartaric acid (L(+)-tartaric acid) [87-69-4]. This enantiomer occurs in grapes as its acid potassium salt (cream of tartar). In the fermentation of wine (qv), this salt forms deposits in the vats free crystallized tartaric acid was first obtained from such fermentation residues by Scheele in 1769. 

AntiweinsSure Butanedioic acid, 2,3-dihydroxy-, (2R,3S)-rel- (R, S )-2,3-Dihydroxybutanedioic acid L-( )-Dihydroxysuccinic acid EINECS 205-696-1 internally compensated tartaric acid meso-Tartaric acid unresolvable tartaric acid. Prepared by raoemization of L-tartaric acid. Crystals mp = 140° 1,66 soluble in H2O (125... 

More elaborate molecules can also have a plane of symmetry. For example, there are only three stereoisomers of tartaric acid (2,3-dihydroxybutanedioic acid). Two of these are chiral but the third is achiral. In the achiral stereoisomer, the substituents are located with respect to each other in such a way as to generate a plane of symmetry. Compounds that contain two or more stereogenic centers but have a plane of symmetry are called meso forms. Because they are achiral, they do not rotate plane polarized light. Note that the Fischer projection structure of meio-tartaric acid reveals the plane of symmetry. 

Tartaric acid serves as the stereochemical connection between the carbohydrates and glyceraldehyde, and is a chiral butanediol that exists in three forms. L-( + )-Tartaric acid, (27, 3/ )-2,3-dihydroxybutanedioic acid 1 (R=H), is referred to as the natural form, and it is widely distributed in nature and classified as a fruit acid. D-( —)-(2 S, 35)-2,3-dihydroxy-butanedioic acid 2 (R=H) is often called unnatural , although it does occur in nature as well. It has the same absolute configuration as D-glyceraldehyde. A third form, called meso-tartaric acid, possess an internal plane of symmetry and is thus inherently racemic and unresolvable. The name tartaric acid is derived from Tartarus, and is probably of medieval and alchemical origin. 

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