| Crotonaldehyde[1] | |
|---|---|
 |
|
| IUPAC name |
(2E)-but-2-enal
|
| Other names | Crotonaldehyde crotoinic aldehyde β-Methacrolein |
| Identifiers | |
| CAS number | 123-73-9  |
| SMILES |
O=C/C=C/C
|
| Properties | |
| Molecular formula | C4H6O |
| Molar mass | 70.09 g mol−1 |
| Appearance | Colorless liquid |
| Density | 0.846 g/cm3 |
| Melting point |
-76.5 °C, 197 K, -106 °F |
| Boiling point |
104.0 °C, 377 K, 219 °F |
| Solubility in methanol | 12.17 M [2] |
| Refractive index (nD) | 1.4362 |
| Hazards | |
| R-phrases | R11 R24/25 R26 R37/38 R41 R48/22 R50 R68 |
| S-phrases | S26 S28 S36/37/39 S45 S61 |
| NFPA 704 |
 3
4
2
|
| (what is this?) (verify) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
|
| Infobox references | |
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.[3]
Contents |
Production and uses
Crotonaldehyde is produced by the aldol condensation of acetaldehyde:
- 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.[3]
Crotonaldehyde is a multifunctional molecule that exhibits diverse reactivity. It is an excellent prochiral dienophile.[4] It is a Michael acceptor. Addition of methylmagnesium chloride affords 3-penten-2-ol.[5]
Safety
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.
See also
References
- ^ Merck Index, 11th Edition, 2599
- ^ Solubility of crotonaldehyde in methanol
- ^ a b 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., http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=CV4P0311; Coll. Vol. 4: 311
- ^ Coburn, E. R. (1955), "3-Penten-2-ol", Org. Synth., http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=CV3P0696; Coll. Vol. 3: 696
External links
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