9433. Tiglic Acid
Nomenclature
CAS number: 80-59-1
(2E)-2-Methyl-2-butenoic acid; (E)-2-methylcrotonic acid; trans-2,3-dimethylacrylic acid. C5H8O2; mol wt 100.12.
C 59.98%, H 8.05%, O 31.96%.
Description and references
The stable isomer of angelic acid. Found as glyceride in croton oil, as butyl ester in the oil of the Roman camomile, Anthemis nobilis L., Compositae, and as geranyl tiglate in oil of geranium. Is formed during the charcoaling of maple wood. Formation by the intestinal roundworm, Ascaris lumbricoides: Bueding, J. Biol. Chem. 202, 505 (1953). Has been found in crude sodium penicillin: Cram, Tishler, J. Am. Chem. Soc. 70, 4238 (1948). Sepn by partition chromatography: Bueding, loc. cit. Synthesis from 2-hydroxy-2-methylbutyronitrile: Crawford, J. Soc. Chem. Ind. London 64, 231 (1945). Review and bibliography: Buckles et al., Chem. Rev. 55, 659-677 (1955).
Properties
Triclinic plates, rods from water. Spicy odor. Vesicant. d 0.972. mp 63.5-64°. bp760 198.5°; bp11.5 95.0-96°. Volatile with steam. nD81 1.4342. pK (25°) 5.02. uv max (H2O): 216-217 nm (ε 10700). Molar heat of combustion 635.1 kcal. Sparingly sol in cold water; freely sol in hot water. Sol in alcohol, ether.Derivative
Calcium salt trihydrate.Ca(C5H7O2)2.3H2O; mol wt 292.34.
Ca 13.71%, C 41.08%, H 6.90%, O 38.31%.
Properties
Leaflets. Much less sol in water than calcium angelate: 100 parts of aq soln satd at 17° contains 6.05 parts of anhydr calcium tiglate.Derivative
Amide.C5H9NO; mol wt 99.13.
C 60.58%, H 9.15%, N 14.13%, O 16.14%.
Properties
Crystals, mp 75-76°.Derivative
Methyl ester.C6H10O2; mol wt 114.14.
C 63.14%, H 8.83%, O 28.03%.
Properties
Liquid; d420 0.9498; bp766 139.6°; nD20 1.4370.Derivative
Ethyl ester.C7H12O2; mol wt 128.17.
C 65.60%, H 9.44%, O 24.97%.
Properties
Liquid; d419.5 0.9247; bp752 156°; bp11 55.5°. nD20 1.4350. Heat of formn at constant vol: 953.2 kcal, at constant pressure: 954.4 kcal.Derivative
Geranyl ester.C15H24O2; mol wt 236.35.
C 76.23%, H 10.24%, O 13.54%.