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by | Mar 15, 2018 | Alstroemeria

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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.[4]

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 many fine chemicals. A prominent industrial example is the crossed aldol condensation with diethyl ketone to give trimethylcyclohexenone, this can be easily converted to trimethylhydroquinone, which is a precursor to the vitamin E.[9] Other derivatives include crotonic acid, 3-methoxybutanol and the food preservative Sorbic acid. Condensation with two equivalents of urea gives a 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. ^ Merck Index, 11th Edition, 2599
  2. ^ a b c d e NIOSH Pocket Guide to Chemical Hazards. "#0157". National Institute for Occupational Safety and Health (NIOSH).
  3. ^ a b "Crotonaldehyde". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
  4. ^ a b c 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. ^ 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. ^ Coburn, E. R. (1947). "3-Penten-2-ol". Org. Synth. 27: 65. doi:10.15227/orgsyn.027.0065.
  7. ^ "Catalysts". 8 January 2011.
  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.
  9. ^ Müller, Marc-André; Schäfer, Christian; Litta, Gilberto; Klünter, Anna-Maria; Traber, Maret G.; Wyss, Adrian; Ralla, Theo; Eggersdorfer, Manfred; Bonrath, Werner (6 December 2022). "100 Years of Vitamin E: From Discovery to Commercialization" (PDF). European Journal of Organic Chemistry. 2022 (45). doi:10.1002/ejoc.202201190.
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