Crotonaldehyde

Crotonaldehyde

Crotonaldehyde

Chemical compound

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.[4]

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Production and reactivity

Crotonaldehyde is produced by the aldol condensation of acetaldehyde:

2 CH3CHO → CH3CH=CHCHO + H2O

Crotonaldehyde is a multifunctional molecule that exhibits diverse reactivity. It is a prochiral dienophile.[5] It is a Michael acceptor. Addition of methylmagnesium chloride produces 3-penten-2-ol.[6]

Polyurethane catalyst N,N,N′,N′-tetramethyl-1,4-butanediamine (also known as NIAX TMBDA) was obtained by hydrogenating the reaction product of crotonaldehyde and dimethylamine.[7]

Uses

Crotonylidene diurea is a specialty fertilizer.[8]

It is 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. It adds two equivalents of urea to give the pyrimidine derivative that is employed as a controlled-release fertilizer. [4]

Safety

Crotonaldehyde is a potent irritant even at the ppm levels. It is not very toxic, with an LD50 of 174 mg/kg (rats, oral).[4]

See also

References

  1. [1]
    Merck Index, 11th Edition, 2599
  2. [2]
    NIOSH Pocket Guide to Chemical Hazards. "#0157". National Institute for Occupational Safety and Health (NIOSH).
  3. [3]
    "Crotonaldehyde". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
  4. [4]
    R. P. Schulz; J. Blumenstein; C. Kohlpaintner (2005). "Crotonaldehyde and Crotonic Acid". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a08_083. ISBN 978-3527306732.
  5. [5]
    Longley Jr., R. I..; Emerson, W. S.; Blardinelli, A. J. (1954). "3,4-Dihydro-2-methoxy-4-methyl-2H-pyran". Org. Synth. 34: 29. doi:10.15227/orgsyn.034.0029.
  6. [6]
    Coburn, E. R. (1947). "3-Penten-2-ol". Org. Synth. 27: 65. doi:10.15227/orgsyn.027.0065.
  7. [7]
    "Catalysts". 8 January 2011.
  8. [8]
    Dittmar, Heinrich; Drach, Manfred; Vosskamp, Ralf; Trenkel, Martin E.; Gutser, Reinhold; Steffens, Günter (2009). "Fertilizers, 2. Types". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.n10_n01. ISBN 978-3527306732.
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