Editing Racemization (section)

== Stereochemistry ==
[[File:Chirality with hands.svg|Two enantiomers of a generic amino acid that is chiral|thumbnail]]
[[Chirality (chemistry)|Chiral]] molecules have two forms (at each point of asymmetry), which differ in their optical characteristics: The ''levorotatory form'' (the ''(−)-form'') will rotate counter-clockwise on the [[Polarization (waves)|plane of polarization]] of a beam of light, whereas the ''dextrorotatory'' form (the ''(+)-form'') will rotate clockwise on the plane of polarization of a beam of light.<ref name = "Kennepohl_2019" /> The two forms, which are non-superposable when rotated in 3-dimensional space, are said to be ''enantiomers''. The notation is not to be confused with <small>D</small> and <small>L</small> naming of molecules which refers to the similarity in structure to [[Glyceraldehyde|<small>D</small>-glyceraldehyde]] and <small>L</small>-glyceraldehyde. Also, (''R'')- and (''S'')- refer to the chemical structure of the molecule based on [[Cahn–Ingold–Prelog priority rules]] of naming rather than rotation of light. R/S notation is the primary notation used for +/- now because D and L notation are used primarily for sugars and amino acids.<ref>{{cite journal | vauthors = Brooks WH, Guida WC, Daniel KG | title = The significance of chirality in drug design and development | journal = Current Topics in Medicinal Chemistry | year = 2011 | volume = 11 | issue = 7 | pages = 760–770 | pmid = 21291399 | pmc = 5765859 | doi = 10.2174/156802611795165098 }}</ref>

Racemization occurs when one pure form of an enantiomer is converted into equal proportion of both enantiomers, forming a [[racemate]]. When there are both equal numbers of dextrorotating and levorotating molecules, the net optical rotation of a racemate is zero. Enantiomers should also be distinguished from [[diastereomers]] which are a type of stereoisomer that have different molecular structures around a [[stereocenter]] and are not mirror images.

Partial to complete racemization of stereochemistry in solutions are a result of [[SN1 reaction|SN1 mechanisms]]. However, when complete inversion of stereochemistry configuration occurs in a [[substitution reaction]], an [[SN2 reaction]] is responsible.<ref>{{cite book | vauthors = Brown WH, Iverson BL, Anslyn E, Foote CS |title=Organic chemistry |date=2017 |publisher=Cengage Learning |location=Boston, Mass. |isbn=978-1-337-51640-2 |edition=Eighth}}</ref>