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Diastereomers have different physical properties (unlike most aspects of enantiomers) and often different chemical reactivity. Diastereomers differ not only in physical properties but also in chemical reactivity — how a compound reacts with others. Glucose and galactose, for instance, are diastereomers. Even though they share the same molar ...
Enantioselective synthesis, also called asymmetric synthesis, [1] is a form of chemical synthesis.It is defined by IUPAC as "a chemical reaction (or reaction sequence) in which one or more new elements of chirality are formed in a substrate molecule and which produces the stereoisomeric (enantiomeric or diastereomeric) products in unequal amounts."
Diastereomers are distinct molecular configurations that are a broader category. [3] They usually differ in physical characteristics as well as chemical properties. If two molecules with more than one chiral centre differ in one or more (but not all) centres, they are diastereomers. All stereoisomers that are not enantiomers are diastereomers.
A mixture of equal amounts of each enantiomer, a racemic mixture or a racemate, does not rotate light. [7] [8] [9] Stereoisomers include both enantiomers and diastereomers. Diastereomers, like enantiomers, share the same molecular formula and are also nonsuperposable onto each other; however, they are not mirror images of each other. [10]
One way to separate enantiomers is to chemically convert them into species that can be separated: diastereomers. Diastereomers, unlike enantiomers, have entirely different physical properties—boiling points, melting points, NMR shifts, solubilities—and they can be separated by conventional means such as chromatography or recrystallization.
Diastereomeric recrystallisation is a method of chiral resolution of enantiomers from a racemic mixture. It differs from asymmetric synthesis, which aims to produce a single enantiomer from the beginning, in that diastereomeric recrystallisation separates two enantiomers that have already mixed into a single solution.
This term has become very popular and commonly used in practice. But the appropriate expression is "enantioselective chromatography". [34] Chiral chromatography has advanced to turn into the most preferred technique for the determination of enantiomeric purity as well as separation of pure enantiomers both on analytical and preparative scale.
Chiral resolution, or enantiomeric resolution, [1] is a process in stereochemistry for the separation of racemic mixture into their enantiomers. [2] It is an important tool in the production of optically active compounds, including drugs. [3]