Pentenoic acid

Pentenoic acid is any of five mono-carboxylic acids whose molecule has an unbranched chain of five carbons connected by three single bonds and one double bond. That is, any compound with one of the formulas HO(O=)C−CH=CH−CH2−CH3 (2-pentenoic), HO(O=)C−CH2−CH=CH−CH3 (3-pentenoic), or HO(O=)C−CH2−CH2−CH=CH2 (4-pentenoic). In the IUPAC-recommended nomenclature, these acids are called pent-2-enoic, pent-3-enoic, and pent-4-enoic, respectively. All these compounds have the empirical formula C
5
H
8
O
2
.

Pentenoic acids are technically mono-unsaturated fatty acids, although they are rare or unknown in biological lipids (fats, waxes, phospholipids, etc.). A salt or ester of such an acid is called a pentenoate.

Geometric isomers

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There are actually two 2-pentenoic acids, distinguished by the conformation of the two single C–C bonds adjacent to the double bond: either on the same side of the double bond's plane (cis or Z configuration) or on opposite sides of it (trans or E configuration).

Likewise, there are two 3-pentenoic acids. On the other hand, there is only one 4-pentenoic acid, since the two hydrogen atoms on the last carbon are symmetrically placed across the double bond's plane.

The full list of pentenoic acids is, therefore:

  • cis-2-pentenoic or (2Z)-pent-2-enoic acid (CAS 16666-42-5, Nikkaji J97.998H, PUBchem 643793).[1][2]
  • trans-2-pentenoic or (2E)-pent-2-enoic acid (CAS 13991-37-2, FDA 1RG66883CF, Nikkaji J97.997J, Beilstein 1720312, PUBchem 638122, JECFA 1804, FEMA 4193). MP ~10 °C; BP ~108 °C at 17 torr, ~198 °C; odor cheesy, sour. Occurs in banana, beer. Flavoring agent.[3]
  • cis-3-pentenoic or (3Z)-pent-3-enoic acid (CAS 33698-87-2, Nikkaji J98.001C, PUBchem 5463134).[4]
  • trans-3-pentenoic or (3E)-pent-3-enoic acid (BP ~52 °C at 4 torr) (CAS 1617-32-9, Nikkaji J98.000E, PUBchem 5282706). BP ~187 °C.[5][6]
  • 4-pentenoic or pent-4-enoic acid, 3-vinylpropionic acid (CAS 591-80-0, FDA D4S77Y29FB, Nikkaji J53.731D, Beilstein 1633696, PUBchem 61138, JECFA 314, FEMA 2843). Dens ~0.975 at 25 °C; IoR ~1.428; MP ~ -23 °C; BP ~83 °C at 12 torr, ~188 °C; sol. water, slightly; odor cheese, mustard.[7] Toxic.[8][9][10]

Esters

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Esters of pentenoic acids include:

Derivatives

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Some derivatives of pentenoic acid include:

[edit]
4-Pentenoic acid
trans-2-pentenoic acid
2-Oxo-4-pentenoic acid.

See also

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References

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  1. ^ Regina Palkovits (2010): "Pentenoic acid pathways for cellulosic biofuels". Angewandte Chemie International Edition, volume 49, issue 26, pages 4336-4338. doi:10.1002/anie.201002061
  2. ^ Perflavory (2020): "(Z)-2-pentenoic acid". Accessed on 2020-08-27.
  3. ^ Perflavory (2020): "(E)-2-pentenoic acid". Accessed on 2020-08-27.
  4. ^ Perflavory (2020): "(Z)-3-pentenoic acid". Accessed on 2020-08-27.
  5. ^ Archibald M Hyson (1950): "Process for producing trans-3-pentenoic acid". US Patent 2586341. Filed on 1950-10-14, granted on 1952-02-19, assigned to EI Du Pont de Nemours; expired on 1969-02-19.
  6. ^ Perflavory (2020): "(E)-3-pentenoic acid". Accessed on 2020-08-27.
  7. ^ Perflavory (2020): "4-pentenoic acid". Accessed on 2020-08-27.
  8. ^ Allen M. Glasgow and H. Peter Chase (1975): "Production of the features of Reye's Syndrome in rats with 4-pentenoic acid". Pediatric Research, volume 9, pages 133-138. Quote: "4-Pentenoic acid, an analog of hypoglycin which is believed to cause Jamaican vomiting sickness, was administered intraperitoneally to rats in an attempt to produce the features of Reye's syndrome in rats." doi:10.1203/00006450-197503000-00005
  9. ^ Allen M. Glasgow and H. Peter Chase (1975): "Inhibition of urea synthesis by 4-pentenoic acid". Biochemical and Biophysical Research Communications, volume 62, issue 2, pages 362-366. doi:10.1016/S0006-291X(75)80147-1
  10. ^ Allen M. Glasgow and H. Peter Chase (1976): "Effect of pent-4-enoic acid, propionic acid and other short-chain fatty acids on citrulline synthesis in rat liver mitochondria.". Biochemical Journal, volume 156, issue 2, pages 301-307. Quote:"... pent-4-enoate inhibits citrulline synthesis by interfering with some aspect of mitochondrial energy metabolism. ... Propionate, butyrate and crotonate also inhibit mitochondrial citrulline synthesis, but much less than pent-4-enoate. ... Acetate, pentanoate, pent-2-enoate, hexanoate, octanoate, isovalerate, tiglylate and alpha-methylbutyrate have little or no effect on mitochondrial citrulline synthesis." doi:10.1042/bj1560301
  11. ^ Perflavory (2020): "ethyl (Z)-2-pentenoate". Accessed on 2020-08-27.
  12. ^ Perflavory (2020): "ethyl (E)-2-pentenoate". Accessed on 2020-08-27.
  13. ^ Perflavory (2020): "butyl 2-pentenoate". Accessed on 2020-08-27.
  14. ^ Perflavory (2020): "ethyl (E)-3-pentenoate". Accessed on 2020-08-27.
  15. ^ Perflavory (2020): "ethyl (Z)-3-pentenoate". Accessed on 2020-08-27.
  16. ^ Perflavory (2020): "isopropyl 3-pentenoate". Accessed on 2020-08-27.
  17. ^ Perflavory (2020): "butyl 3-pentenoate". Accessed on 2020-08-27.
  18. ^ Ching Y. Tseng, John B. Hall, Manfred Hugo Vock, Joaquin Vinals, and Edward J. Shuster (1975): "Flavoring with cis esters of 2-methyl-3-pentenoic acid". US Patent 2586341. Filed on 1975-05-09, granted on 1976-12-28, assigned to International Flavors and Fragrances Inc; expired on 1993-12-28.
  19. ^ Wolfgang Löscher, Heinz Nau, Christian Marescaux, and Marguerite Vergnes (1984): "Comparative evaluation of anticonvulsant and toxic potencies of valproic acid and 2-en-valproic acid in different animal models of epilepsy". European Journal of Pharmacology, volume 99, issues 2–3, pages 211-218. doi:10.1016/0014-2999(84)90243-7
  20. ^ Perflavory (2020): "(Z)-2-methyl-2-pentenoic acid". Accessed on 2020-08-27.
  21. ^ Perflavory (2020): "(E)-2-methyl-2-pentenoic acid". Accessed on 2020-08-27.
  22. ^ Perflavory (2020): "2-methyl-2-pentenoic acid (E/Z mix)". Accessed on 2020-08-27.
  23. ^ Perflavory (2020): "hexyl 2-methyl-4-pentenoate". Accessed on 2020-08-27.