Crotonic acid

Crotonic acid

Names
IUPAC name (E)-2-butenoic acid
Other names trans-2-butenoic acid beta-methylacrylic acid 3-methylacrylic acid (E)-2-butenoic acid
Identifiers
CAS Number	107-93-7
ChEBI	CHEBI:41131
ChEMBL	ChEMBL1213528
ChemSpider	552744
DrugBank	DB02074
Jmol interactive 3D	Image Image
PubChem	637090
InChI InChI=1S/C4H6O2/c1-2-3-4(5)6/h2-3H,1H3,(H,5,6)/b3-2+ Key: LDHQCZJRKDOVOX-NSCUHMNNSA-N InChI=1/C4H6O2/c1-2-3-4(5)6/h2-3H,1H3,(H,5,6)/b3-2+ Key: LDHQCZJRKDOVOX-NSCUHMNNBH
SMILES C/C=C/C(O)=O O=C(O)/C=C/C
Properties
Chemical formula	C4H6O2
Molar mass	86.09 g/mol
Density	1.02 g/cm^3
Melting point	70 to 73 °C (158 to 163 °F; 343 to 346 K)
Boiling point	185 to 189 °C (365 to 372 °F; 458 to 462 K)
Acidity (pKa)	4.69 [1]
Hazards
Safety data sheet	SIRI.org
Related compounds
Other anions	crotonate
Related carboxylic acids	propionic acid acrylic acid butyric acid succinic acid malic acid tartaric acid fumaric acid pentanoic acid
Related compounds	butanol butyraldehyde crotonaldehyde 2-butanone
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Crotonic acid, or trans-2-butenoic acid, is a short-chain unsaturated carboxylic acid, described by the formula CH₃CH=CHCO₂H. Crotonic acid is so named because it was erroneously thought to be a saponification product of croton oil. It crystallizes as needles from hot water.

Racemic threonine can be prepared from crotonic acid by alpha-functionalization using mercury(II) acetate.^[2]

See also

• Crotyl
• Crotonaldehyde
• Crotyl alcohol
• Isocrotonic acid
• Methacrylic acid

References

1. Dawson, R. M. C., et al., Data for Biochemical Research, Oxford, Clarendon Press, 1959.
2. Carter, H. E.; West, H. D. (1955). "dl-Threonine". Org. Synth.; Coll. Vol. 3, p. 813

 This article incorporates text from a publication now in the public domain: Chisholm, Hugh, ed. (1911). Encyclopædia Britannica (11th ed.). Cambridge University Press.