Editing Tartaric acid (section)

== Stereochemistry ==
{{stack|[[File:TartrateCrystal.svg|thumb|class=skin-invert-image|Tartaric acid crystals drawn as if seen through an [[optical microscope]]]]|float=right}}

Naturally occurring form of the acid is '''dextro tartaric&nbsp;acid ''' or '''<small>L</small>-(+)-tartaric&nbsp;acid''' (obsolete name [[Descriptor (Chemistry)#dl|''d'']]-tartaric acid).  Because it is available naturally, it is cheaper than its [[enantiomer]] and the [[meso isomer]]. The ''dextro'' and ''levo'' prefixes are archaic terms.<ref>{{Cite web |url=https://cosmolearning.org/video-lectures/stereochemical-nomenclature-racemization-and-resolution-6674/ |title=Lecture 28: Stereochemical Nomenclature; Racemization and Resolution &#124; CosmoLearning Chemistry |website=CosmoLearning}}</ref> Modern textbooks refer to the natural form as (2''R'',3''R'')-tartaric acid '''('''<small>L</small>'''-(+)-tartaric acid)''', and its enantiomer as (2''S'',3''S'')-tartaric acid '''('''D'''-(−)-tartaric acid)'''.  The ''meso'' diastereomer is referred to as (2''R'',3''S'')-tartaric acid or (2''S'',3''R'')-tartaric acid.

* Dextro and levo form [[Crystal structure|monoclinic sphenoidal]] crystals<ref>{{cite journal |last1=W, T, Astbury |title=The Crystalline Structure and Properties of Tartaric Acid |journal=Proc. R. Soc. A |date=Feb 1923 |volume=102|issue=718 |pages=506–528 | doi=10.1098/rspa.1923.0010 |bibcode=1923RSPSA.102..506A |doi-access=free }}, based on P. Groth’s “Chemische Krystallographie".</ref> and [[orthorhombic]] crystals.
* Racemic tartaric acid forms [[monoclinic]]<ref name=CRC49>CRC Handbook of Chemistry and Physics, 49th edition.</ref> and [[triclinic]] crystals ([[space group]] P{{overline|1}}).<ref>{{cite web|date=2008 |last1=Samantha Callear and Michael Hursthouse |title=D-Tartaric acid |url=http://www.crystallography.net/cod/1519959.html |website=Crystallography Open Database}}</ref><ref>{{cite journal |display-authors=etal|last1=Paul Luner |title=(+-)-Tartaric acid |journal=Acta Crystallographica Section C |date=Jul 2002 |volume=58 |issue=6 |pages=o333–o335 |doi=10.1107/S0108270102006650 |pmid=12050433 |bibcode=2002AcCrC..58O.333L |url=https://www.researchgate.net/publication/11324000}}, {{cite web |title=(±)-Tartaric acid |url=http://www.crystallography.net/cod/2012731.html |website=Crystallography Open Database|year=2002 }}</ref> 
* Anhydrous meso tartaric acid form two anhydrous [[polymorphism (materials science)|polymorphs]]: triclinic and orthorhombic.
* Monohydrated meso tartaric acid crystallizes as monoclinic and triclinic polymorphys depending on the temperature at which crystallization from aqueous solution occurs.<ref>{{cite journal |last1=G. A. Bootsma and J. C. Schoone |title=Crystal Structures of Meso Tartaric Acid |journal=Acta Crystallogr.  |date=1967 |volume=22|issue=4 |pages=522–532 | doi=10.1107/S0365110X67001070 |bibcode=1967AcCry..22..522B |url=https://scripts.iucr.org/cgi-bin/paper?a05502|doi-access=free }}</ref>
Tartaric acid in [[Fehling's solution]] binds to copper(II) ions, preventing the formation of insoluble hydroxide salts.

{| class="wikitable" style="text-align:center;"
! colspan="2" | <small>DL</small>-tartaric acid ([[racemic acid]]) <small>(when in 1:1 ratio)</small>
! rowspan="2" | mesotartaric acid
|-
! dextrotartaric acid<br/><small>(L-(+)-tartaric acid)</small>
! levotartaric acid<br/><small>(D-(−)-tartaric acid)</small>
|-
| width="150" | [[File:L-tartaric acid.png|class=skin-invert-image]]
| width="150" | [[File:D-tartaric acid.png|class=skin-invert-image]]
| width="270" | [[File:Meso-Weinsäure Spiegel.svg|150 px|class=skin-invert-image]]
|}

{{clear}}
{| class="wikitable"
|+ Forms of tartaric acid
|-
! [[Common name]]
! Tartaric acid
! Levotartaric acid
! Dextrotartaric acid
! Mesotartaric acid
! Racemic acid
|-
! Synonyms
| 
| style="vertical-align:top" | (2''S'',3''S'')-tartaric acid <br/> (''S'',''S'')-tartaric acid <br/> (−)-tartaric acid <br/> ''l''-tartaric acid <small>''(obsolete)''</small> <br/> levotartaric acid <br/> {{sc|D}}-tartaric acid <br/> {{sc|D}}-threaric acid <br/>("unnatural isomer")<ref>{{Cite web |url=https://pubchem.ncbi.nlm.nih.gov/compound/439655 |title=d-Tartaric acid |website=[[PubChem]]}}</ref>
| style="vertical-align:top" | (2''R'',3''R'')-tartaric acid <br/> (''R'',''R'')-tartaric acid <br/> (+)-tartaric acid <br/> ''d''-tartaric acid <small>''(obsolete)''</small> <br/> {{sc|L}}-tartaric acid <br/> {{sc|L}}-threaric acid <br/>("natural isomer")<ref>{{Cite web |url=https://pubchem.ncbi.nlm.nih.gov/compound/L-tartaric_acid |title=L-(+)-Tartaric acid |website=[[PubChem]] |url-status=dead |archive-url=https://web.archive.org/web/20150516011103/https://pubchem.ncbi.nlm.nih.gov/compound/L-tartaric_acid#section=Top |archive-date=May 16, 2015}}</ref>
| style="vertical-align:top" | (2''R'',3''S'')-tartaric acid <br/> ''meso''-tartaric acid <br/> erythraric acid
| style="vertical-align:top" | ''rac''-(2''R'',3''S'')-tartaric acid <br/> (2''RS'',3''SR'')-tartaric acid <br/> (±)-tartaric acid <br/> {{sc|DL}}-tartaric acid <br/> ''dl''-tartaric acid <small>''(obsolete)''</small> <br/> paratartaric acid <br/> uvic acid
|-
! [[PubChem]]
| {{PubChemCID|875}}
| {{PubChemCID|439655}}
| {{PubChemCID|444305}}
| {{PubChemCID|78956}}
| {{PubChemCID|5851}}
|-
! [[EINECS number]]
| 
| {{EINECS|205-695-6}}
| {{EINECS|201-766-0}}
| {{EINECS|205-696-1}}
| {{EINECS|205-105-7}}
|-
! [[CAS number]]
| 526-83-0
| 147-71-7
| 87-69-4
| 147-73-9
| 133-37-9
|}