7. Abietic Acid

Nomenclature

CAS number: 514-10-3
(1R,4aR,4bR,10aR)-1,2,3,4,4a,4b,5,6,10,10a-Decahydro-1,4a-dimethyl-7-(1-methylethyl)-1-phenanthrenecarboxylic acid; 13-isopropylpodocarpa-7,13-dien-15-oic acid; sylvic acid.
C20H30O2; mol wt 302.45.
C 79.42%, H 10.00%, O 10.58%.

Description and references

A widely available organic acid, prepared by isomerization of rosin: Harris, Sanderson, Org. Synth. coll. vol. IV, 1 (1963); Fieser, Fieser, The Chemistry of Natural Products Related to Phenanthrene (New York, 3rd ed., 1949). Synthesis from dehydroabietic acid: A. W. Burgstahler, L. W. Worden, J. Am. Chem. Soc. 83, 2587 (1961) DOI; E. Wenkert et al., ibid. 86, 2038 (1964) DOI. Chromatographic study: A. G. Douglas, T. G. Powell, J. Chromatogr. 43, 241 (1969) DOI. Metabolism in rabbits: Y. Asakawa et al., Xenobiotica 16, 753 (1986) PubMed.

Chemical structure

Properties

Monoclinic plates from alcohol + water, mp 172-175°. [α]D24 106° (c = 1 in abs alc). uv max: 235, 241.5, 250 nm (ε 19500, 22000, 14300). Insol in water. Sol in alc, benzene, chloroform, ether, acetone, carbon disulfide, dil NaOH soln. Commercial abietic acid made by heating rosin alone or with acids may be glassy or partly crystalline, usually of yellow color and melting as low as 85°.

Derivative

Methyl ester see Methyl Abietate.

Use

Manufacture of esters (ester gums), e.g., methyl, vinyl and glyceryl esters for use in lacquers and varnishes. Manufacture of “metal resinates”, soaps, plastics and paper sizes. Assists growth of lactic and butyric acid bacteria.