|CAS number||, (E) , (Z)|
|Jmol-3D images||Image 1|
|Molar mass||70.09 g mol−1|
|Odor||pungent, suffocating odor|
|Melting point||−76.5 °C (−105.7 °F; 196.7 K)|
|Boiling point||104.0 °C (219.2 °F; 377.1 K)|
|Solubility||very soluble in ethanol, ethyl ether, acetone
soluble in chloroform
miscible in benzene
|Refractive index (nD)||1.4362|
|R-phrases||R11 R24/25 R26 R37/38 R41 R48/22 R50 R68|
|S-phrases||S26 S28 S36/37/39 S45 S61|
|Flash point||13 °C (55 °F; 286 K)|
|Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)|
|(what is: / ?)|
Crotonaldehyde is a chemical compound with the formula CH3CH=CHCHO. The compound is usually sold as a mixture of the E- and Z-isomers, which differ with respect to the relative position of the methyl and formyl groups. The E-isomer is more common (data given in Table is for the E-isomer). This lachrymatory liquid is moderately soluble in water and miscible in organic solvents. As an unsaturated aldehyde, crotonaldehyde is a versatile intermediate in organic synthesis. It occurs in a variety of foodstuffs, e.g. soybean oils.
Production and uses
- 2 CH3CHO → CH3CH=CHCHO + H2O
Its main application is as a precursor to fine chemicals. Sorbic acid, a food preservative, and trimethylhydroquinone, a precursor to the vitamin E, are prepared from crotonaldehyde. Other derivatives include crotonic acid and 3-methoxybutanol.
Crotonaldehyde is a multifunctional molecule that exhibits diverse reactivity. It is an excellent prochiral dienophile. It is a Michael acceptor. Addition of methylmagnesium chloride affords 3-penten-2-ol.
Crotonaldehyde is an irritant. It is listed as an "extremely hazardous substance" as defined by the U.S. Emergency Planning and Community Right-to-Know Act. It occurs widely in nature. It is used to make preservatives.
- Merck Index, 11th Edition, 2599
- R. P. Schulz, J. Blumenstein, C. Kohlpaintner "Crotonaldehyde and Crotonic Acid" Ullmann's Encyclopedia of Chemical Technology, Wiley-VCH, Weinheim: 2005. doi:10.1002/14356007.a08_083
- Longley, Jr., R. I..; Emerson, W. S.; Blardinelli, A. J. (1963), "3,4-Dihydro-2-methoxy-4-methyl-2H-pyran", Org. Synth.; Coll. Vol. 4: 311
- Coburn, E. R. (1955), "3-Penten-2-ol", Org. Synth.; Coll. Vol. 3: 696