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A meso compound or meso isomer is an optically inactive isomer in a set of stereoisomers, at least two of which are optically active. [1] [2] This means that despite containing two or more stereocenters, the molecule is not chiral. A meso compound is superposable on its mirror image (not to be confused with superimposable, as any two objects ...
1,2,3,4-Butanetetracarboxylic acid is an organic compound with the formula HO 2 CCH 2 CH(CO 2 H)CH(CO 2 H)CH 2 CO 2 H. It is one of the simplest stable tetracarboxylic acids. The compound exists as two diastereomers, meso and the (R,R)/(S,S) pair. All are white solids. The compound is produced by oxidation of tetrahydrophthalic anhydride. [1]
Pure enantiomers also exhibit the phenomenon of optical activity and can be separated only with the use of a chiral agent. In nature, only one enantiomer of most chiral biological compounds, such as amino acids (except glycine, which is achiral), is present. Enantiomers differ by the direction they rotate polarized light: the amount of a chiral ...
There are three common naming conventions for specifying one of the two enantiomers (the absolute configuration) of a given chiral molecule: the R/S system is based on the geometry of the molecule; the (+)- and (−)- system (also written using the obsolete equivalents d- and l-) is based on its optical rotation properties; and the D/L system is based on the molecule's relationship to ...
In a mixture of enantiomers, these methods can help quantify the optical purity by integrating the area under the NMR peak corresponding to each stereoisomer. Accuracy of integration can be improved by inserting a chiral derivatizing agent with a nucleus other than hydrogen or carbon, then reading the heteronuclear NMR spectrum: for example ...
Of the three stereoisomers, two are enantiomers (levo- and dextro-2,3-butanediol) and one is a meso compound. [ 1 ] [ 2 ] The enantiomeric pair have (2 R , 3 R ) and (2 S , 3 S ) configurations at carbons 2 and 3, while the meso compound has configuration (2 R , 3 S ) or, equivalently, (2 S , 3 R ).
An enantiomeric pair (S,S)- and (R,R)-ethambutol, along with the achiral stereoisomer called meso-form, it holds a diastereomeric relationship with the optically active stereoisomers. The activity of the drug resides in the (S,S)-enantiomer which is 500 and 12 fold more potent than the (R,R)-ethambutol and the meso-form. The drug had initially ...
The stereochemical term enantiotopic refers to the relationship between two groups in a molecule which, if one or the other were replaced, would generate a chiral compound. The two possible compounds resulting from that replacement would be enantiomers. For example, the two hydrogen atoms attached to the second carbon in butane are enantiotopic.