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  Y
3D model (JSmol)	Interactive image
ChEMBL	ChEMBL1098368
ChemSpider	70589
ECHA InfoCard	100.022.478
EC Number	224-724-3
PubChem CID	78213
UNII	821BB4R21V  Y
CompTox Dashboard (EPA)	DTXSID20196252
InChI InChI=1S/C18H16O4/c19-17(20)15-13(11-7-3-1-4-8-11)16(18(21)22)14(15)12-9-5-2-6-10-12/h1-10,13-16H,(H,19,20)(H,21,22) Key: QWFRRFLKWRIKSZ-UHFFFAOYSA-N
SMILES 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
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H301, H315, H319, H335
Precautionary statements	P261, P264, P264+P265, P270, P271, P280, P301+P316, P302+P352, P304+P340, P305+P351+P338, P319, P321, P330, P332+P317, P337+P317, P362+P364, P403+P233, P405, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

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

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.