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  2. Diastereomer - Wikipedia

    en.wikipedia.org/wiki/Diastereomer

    In stereochemistry, diastereomers (sometimes called diastereoisomers) are a type of stereoisomer. [1] Diastereomers are defined as non-mirror image, non-identical stereoisomers. Hence, they occur when two or more stereoisomers of a compound have different configurations at one or more (but not all) of the equivalent (related) stereocenters and ...

  3. Meso compound - Wikipedia

    en.wikipedia.org/wiki/Meso_compound

    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 can ...

  4. Cahn–Ingold–Prelog priority rules - Wikipedia

    en.wikipedia.org/wiki/Cahn–Ingold–Prelog...

    A meso compound is superposable on its mirror image, therefore it reduces the number of stereoisomers predicted by the 2 n rule. This occurs because the molecule obtains a plane of symmetry that causes the molecule to rotate around the central carbon–carbon bond. [12] One example is meso-tartaric acid, in which (R,S) is the same as the (S,R ...

  5. 2,3-Butanediamine - Wikipedia

    en.wikipedia.org/wiki/2,3-Butanediamine

    2,3-Butanediamines can be prepared by hydrolyzing 2-ethoxy-4,5-dihydro-4,5-dimethylimidazole with barium hydroxide. [4] Alternative, it is produced by reduction of dimethylglyoxime with lithium aluminium hydride. [5] The meso and the d,l diastereomers can be separated by fractional crystallization of the hydrochlorides.

  6. Stereoisomerism - Wikipedia

    en.wikipedia.org/wiki/Stereoisomerism

    Stereochemistry focuses on stereoisomers, red boxes in the picture. In stereochemistry, stereoisomerism, or spatial isomerism, is a form of isomerism in which molecules have the same molecular formula and sequence of bonded atoms (constitution), but differ in the three-dimensional orientations of their atoms in space. [1][2] This contrasts with ...

  7. Stereocenter - Wikipedia

    en.wikipedia.org/wiki/Stereocenter

    Stereocenter. In stereochemistry, a stereocenter of a molecule is an atom (center), axis or plane that is the focus of stereoisomerism; that is, when having at least three different groups bound to the stereocenter, interchanging any two different groups creates a new stereoisomer. [ 1 ][ 2 ] Stereocenters are also referred to as stereogenic ...

  8. Diastereomeric recrystallization - Wikipedia

    en.wikipedia.org/wiki/Diastereomeric_re...

    The strategy of diastereomeric recrystallisation involves two steps. The first step is to convert the enantiomers into diastereomers by way of a chemical reaction. A mixture of enantiomers may contain two isomers of a molecule with one chiral center. After adding a second chiral center in a determined location, the two isomers are still ...

  9. Topicity - Wikipedia

    en.wikipedia.org/wiki/Topicity

    Enantiotopic groups are identical and indistinguishable except in chiral environments. For instance, the CH 2 hydrogens in ethanol (CH 3 CH 2 OH) are normally enantiotopic, but can be made different (diastereotopic) if combined with a chiral center, for instance by conversion to an ester of a chiral carboxylic acid such as lactic acid, or if coordinated to a chiral metal center, or if ...