Crotonaldehyde
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| Names | |
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| IUPAC name
(2E)-but-2-enal
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| Other names
Crotonaldehyde
crotoinic aldehyde β-Methacrolein | |
| Identifiers | |
3D model (JSmol)
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| ECHA InfoCard | 100.021.846 |
CompTox Dashboard (EPA)
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| Properties | |
| C4H6O | |
| Molar mass | 70.091 g·mol−1 |
| Appearance | Colorless liquid |
| Density | 0.846 g/cm3 |
| Melting point | −76.5 °C (−105.7 °F; 196.7 K) |
| Boiling point | 104.0 °C (219.2 °F; 377.1 K) |
| Solubility in methanol | 12.17 M [2] |
Refractive index (nD)
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1.4362 |
| Hazards | |
| NFPA 704 (fire diamond) | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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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]
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". Organic Syntheses
{{cite journal}}: CS1 maint: multiple names: authors list (link); Collected Volumes, vol. 4, p. 311. - ^ Coburn, E. R. (1955). "3-Penten-2-ol". Organic Syntheses; Collected Volumes, vol. 3, p. 696.