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 ;
3D model (JSmol)	Interactive image;
ChEMBL	ChEMBL1098368;
ChemSpider	70589;
ECHA InfoCard	100.022.478
EC Number	224-724-3;
PubChem CID	78213;
UNII	821BB4R21V ;
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:[1]
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. The preparation of truxillic acids provided an early example of organic photochemistry.