Tiglic acid

Tiglic acid
Names
	Preferred IUPAC name (2E)-2-Methylbut-2-enoic acid
	Other names (E)-2-Methylbut-2-enoic acid; Cevadic acid; Sabadillic acid; Tiglinic acid
Identifiers
CAS Number	80-59-1 ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:9592 ;
ChemSpider	111629 ;
ECHA InfoCard	100.001.178
IUPHAR/BPS	6499;
PubChem CID	125468;
UNII	I5792N03HC ;
CompTox Dashboard (EPA)	DTXSID80883257 ;
	InChI InChI=1S/C5H8O2/c1-3-4(2)5(6)7/h3H,1-2H3,(H,6,7)/b4-3+ Key: UIERETOOQGIECD-ONEGZZNKSA-N ; InChI=1/C5H8O2/c1-3-4(2)5(6)7/h3H,1-2H3,(H,6,7)/b4-3+ Key: UIERETOOQGIECD-ONEGZZNKBL;
	SMILES O=C(O)/C(=C/C)C;
Properties
Chemical formula	C5H8O2
Molar mass	100.116 g/mol
Density	0.9641 g/cm3 (76 °C)
Melting point	63.5 to 64 °C (146.3 to 147.2 °F; 336.6 to 337.1 K)
Boiling point	198.5 °C (389.3 °F; 471.6 K)
Acidity (pKa)	4.96
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Tiglic acid is a monocarboxylic unsaturated organic acid. It is found in croton oil and in several other natural products. It has also been also isolated from the defensive secretion of certain beetles.