Crotonyl
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Crotonyl".

Crotonic acid
IUPAC name	(E)-2-butenoic acid
Other names	trans-2-butenoic acid beta-methylacrylic acid 3-methylacrylic acid
Identifiers
CAS number	[107-93-7]
SMILES	C/C=C/C(O)=O
Properties
Molecular formula	C4H6O2
Molar mass	86.09 g/mol
Density	1.02 g/cm3
Melting point	70-73 °C
Boiling point	185-189 °C
Hazards
MSDS	Sciencelab MSDS
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and 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.

Isocrotonic acid (or quartenylic acid) is the cis analogue of crotonic acid. It is an oil, possessing a smell similar to that of brown sugar. It boils at 171.9°C, concomitant with conversion into crotonic acid. Isomerizaton is complete when the cis acid is heated to 170-180°C in a sealed tube.

Racemic threonine can be prepared from crotonic acid by alpha-functionalization using mercury(II) acetate.^[1]

See also

• Crotyl
• Crotonaldehyde
• Crotyl alcohol
• Methacrylic acid

References

1. ^ Carter, H. E.; West, H. D. (1955). "dl-Threonine". Org. Synth.; Coll. Vol. 3: 813. 

This article incorporates text from the Encyclopædia Britannica Eleventh Edition, a publication now in the public domain.