Truxillic acid

Truxillic acid
Names
IUPAC name
7,8′-Cyclo-8,7′-neolignane-9,9′-dioic acid
Systematic IUPAC name
2,4-Diphenylcyclobutane-1,3-dicarboxylic acid
Identifiers
CAS Number
  • 4462-95-7 checkY
3D model (JSmol)
  • Interactive image
ChemSpider
  • 70589
ECHA InfoCard 100.022.478 Edit this at Wikidata
PubChem CID
  • 78213
UNII
  • 821BB4R21V checkY
CompTox Dashboard (EPA)
  • DTXSID20196252 Edit this at Wikidata
  • OC(C1C(C2=CC=CC=C2)C(C(O)=O)C1C3=CC=CC=C3)=O
Properties
Chemical formula
 C18H16O4
Molar mass 296.322 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references
Chemical compound

Truxillic acids are any of several crystalline stereoisomeric cyclic dicarboxylic acids with the formula (C6H5C2H2(CO2H)2. They are colorless solids. These compounds are obtained by the [2 + 2] photocycloadditions of cinnamic acid where the two trans alkenes react head-to-tail. The isolated stereoisomers are called truxillic acids.[1] The preparation of truxillic acids provided an early example of organic photochemistry.[2]

Cinnamic Acid CycloAddition
Cinnamic Acid CycloAddition

Occurrence and reactions

These compounds are found in a variety of plants, for example in coca.[3][4] Incarvillateine, an alkaloid from the plant Incarvillea sinensis, is a derivative of α-truxillic acid.

Upon heating, truxillic acids undergo cracking to give cinnamic acid.[5]

Isomers

Truxillic acid can exist in five stereoisomers.[6][7]

Truxillic acid isomers
Isomer a b c d e f
α-truxillic acid
(cocaic acid[8])		 COOH H H C6H5 H COOH
γ-truxillic acid COOH H H C6H5 COOH H
ε-truxillic acid H COOH C6H5 H H COOH
peri-truxillic acid COOH H C6H5 H COOH H
epi-truxillic acid COOH H C6H5 H H COOH

Below are the five stereoisomers of truxillic acid, called alpha, gamma, epsilon, peri, and epi. These are shown both in a 2D skeletal diagram with stereocenters indicated and a 3D rendering of the structural geometry of the isomers themselves.

See also

  • Truxinic acids are isomers of the truxillic acids with phenyl groups on adjacent methyne centers.

References

  1. ^ Cohen, M. D.; Schmidt, G. M. J.; Sonntag, F. I. (1964). "Topochemistry. II. The photochemistry of trans-cinnamic acids". J. Chem. Soc.: 2000–2013. doi:10.1039/jr9640002000.
  2. ^ Roth, Heinz D. (1989). "The Beginnings of Organic Photochemistry". Angewandte Chemie International Edition in English. 28 (9): 1193–1207. doi:10.1002/anie.198911931.
  3. ^ Liebermann, C. (1888). "Ueber Cinnamylcocaïn". Berichte der Deutschen Chemischen Gesellschaft. 21 (2): 3372–3376. doi:10.1002/cber.188802102223.
  4. ^ Krauze-Baranowska, Miroslawa (2002). "Truxillic and truxinic acids-occurrence in plant kingdom". Acta Poliniae Pharmaceutica-Drug Research. 59 (5): 403–410. PMID 12602803.
  5. ^ Hein, Sara M. (2006). "An Exploration of a Photochemical Pericyclic Reaction Using NMR Data". Journal of Chemical Education. 83 (6): 940–942. Bibcode:2006JChEd..83..940H. doi:10.1021/ed083p940.
  6. ^ Stoermer, R.; Bachér, F. (1924). "Zur Stereoisomerie der Truxillsäuren und über die Auffindung der letzten Säure dieser Gruppe (VIII.)". Berichte der Deutschen Chemischen Gesellschaft (A and B Series). 57: 15–23. doi:10.1002/cber.19240570105.
  7. ^ Agarwai, O. P. (2011). Organic Chemistry Reactions and Reagents. Krishna Prakashan Media. ISBN 978-8187224655.
  8. ^ "ChemSpider ID 10218892". ChemSpider. Retrieved 15 October 2016.