5164. Isocrotonic Acid
Nomenclature
CAS number: 503-64-0
(2Z)-2-Butenoic acid; cis-2-butenoic acid; cis-crotonic acid. C4H6O2; mol wt 86.09.
C 55.81%, H 7.02%, O 37.17%.
Description and references
Prepd by reacting acetaldehyde with malonic acid in the presence of pyridine: v. Auwers et al., Ann. 432, 46 (1923); from ethyl acetoacetate: Hatch, Nesbitt, J. Am. Chem. Soc. 72, 727 (1950); from but-2-ynoic acid: Allan et al., J. Chem. Soc. 1955, 1862; from CH3CH=CHMgBr + CO2: Normant, Maitte, Bull. Soc. Chim. Fr. 1956, 1439. Structure: v. Auwers, Wissebach, Ber. 56, 715 (1923); Plisov, Bogatskii, Zh. Obshch. Khim. 27, 360 (1957), C.A. 51, 15401c (1957). Review: W. Blau et al., in Ullmann's Encyclopedia of Industrial Chemistry vol. A8 (VCH, Weinheim, 5th ed., 1987) pp 83-89.
Properties
Liquid. bp5 55-56°; bp10 62-64°; bp760 168-169°. mp 15°; crystallized from pentane. d420 1.0267. nD14 1.4483. nD20 1.4450. uv max (95% ethanol): 205.5 nm (ε 13500).Derivative
Methyl ester.Nomenclature
CAS number: 4358-59-2
C5H8O2; mol wt 100.12.
C 59.98%, H 8.05%, O 31.96%.
Properties
Liquid. bp 118°. nD20 1.4175. uv max (95% ethanol): 205.5 nm (ε 14000).Derivative
Benzyl ester.Nomenclature
CAS number: 92758-75-3
C11H12O2; mol wt 176.21.
C 74.98%, H 6.86%, O 18.16%.