mesaconic acid
{{Chembox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 438444350
| ImageFile = Mesaconic-acid-2D-skeletal.svg
| ImageSize = 180px
| ImageName = Skeletal formula
| ImageFile1 = Mesaconic-acid-3D-balls.png
| ImageName1 = Ball-and-stick model
| PIN = (2E)-2-Methylbut-2-enedioic acid
| OtherNames =
|Section1={{Chembox Identifiers
| CASNo_Ref = {{cascite|correct|??}}
| CASNo = 498-24-8
| PubChem = 638129
| SMILES = OC(/C(C)=C/C(O)=O)=O
| EINECS = 207-859-2
| ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}}
| ChemSpiderID = 10289044
| InChI = 1/C5H6O4/c1-3(5(8)9)2-4(6)7/h2H,1H3,(H,6,7)(H,8,9)/b3-2+
| InChIKey = HNEGQIOMVPPMNR-NSCUHMNNBN
| StdInChI_Ref = {{stdinchicite|changed|chemspider}}
| StdInChI = 1S/C5H6O4/c1-3(5(8)9)2-4(6)7/h2H,1H3,(H,6,7)(H,8,9)/b3-2+
| StdInChIKey_Ref = {{stdinchicite|changed|chemspider}}
| StdInChIKey = HNEGQIOMVPPMNR-NSCUHMNNSA-N
| RTECS =
| MeSHName =
| ChEBI_Ref = {{ebicite|changed|EBI}}
| ChEBI = 16600
| 3DMet = B00338
| UNII = 90UTM639KK
| KEGG_Ref = {{keggcite|correct|kegg}}
| KEGG = C01732
}}
|Section2={{Chembox Properties
| Formula = C5H6O4
| MolarMass = 130.10 g/mol
| Appearance =
| Density = 1.31 g/cm3
| MeltingPtC = 204 to 205
| MeltingPt_notes =
| BoilingPtC = 250
| BoilingPt_notes = (decomposes)
| Solubility =
}}
|Section3={{Chembox Hazards
| MainHazards =
| FlashPt =
| AutoignitionPt =
| GHSPictograms = {{GHS07}}
| GHSSignalWord = Warning
| HPhrases = {{H-phrases|315|319|335}}
| PPhrases = {{P-phrases|261|264|271|280|302+352|304+340|305+351+338|312|321|332+313|337+313|362|403+233|405|501}}
}}
}}
Mesaconic acid is one of several isomeric carboxylic acids obtained from citric acid. It is a colorless solid.
Synthesis and reactions
It is prepared from citric acid, which is first converted to itaconic anhydride by dehydration and decarboxylation. Itaconic acid anhydride is isomerized to citraconic anhydride, which is hydrolyzed and the resulting acid further isomerized under acid-catalysis to give mesaconic acid.{{cite journal|title=Mesaconic Acid|author=R. L. Shriner |author2=S. G. Ford |author3=L. J. Roll
|journal=Org. Synth.|year=1931|volume=11|page=74|doi=10.15227/orgsyn.011.0074}}
Hydration of mesaconic acid, a conversion catalyzed by mesaconyl-C4-CoA hydratase, gives citramalic acid.{{cite journal |doi=10.1128/AEM.02473-10|title=Ecological Aspects of the Distribution of Different Autotrophic CO 2 Fixation Pathways|year=2011|last1=Berg|first1=Ivan A.|journal=Applied and Environmental Microbiology|volume=77|issue=6|pages=1925–1936|pmid=21216907|pmc=3067309|bibcode=2011ApEnM..77.1925B}}
History
This acid was studied for the first time by Jacobus H. van 't Hoff in 1874.{{cite web|title=Mesaconic acid |url=http://dbhs.wvusd.k12.ca.us/webdocs/Chem-History/Van't-Hoff-1874.html |access-date=September 8, 2005 |archive-url=https://web.archive.org/web/20051117102410/http://dbhs.wvusd.k12.ca.us/webdocs/Chem-History/Van%27t-Hoff-1874.html |archive-date=November 17, 2005 }} It was later shown to be produced by Clostridium tetanomorphum. Further studies showed that this organic compound is involved in the biosynthesis of vitamin B12. It is a competitive inhibitor of fumarate reduction.{{cite web|title=Barker, Horace Albert|work=The Stadtman Way: The Story of Two Biochemists at NIH|publisher=Office of NIH History|url=http://www.history.nih.gov/exhibits/stadtman/bios.htm#Barker
The compound has been considered as a renewable precursor to the commodity chemical methacrylic acid.{{cite journal|title=Recent advances in plant-based vinyl ester resins and reactive diluents|author=Santosh K. Yadav |author2=Kevin M. Schmalbach |author3=Emre Kinaci |author4=Joseph F. Stanzione III |author5=Giuseppe R. Palmese |journal=European Polymer Journal|year=2018|volume=98 |page=199–215|doi=10.1016/j.eurpolymj.2017.11.002|doi-access=free}}