6881. o-Orsellinic Acid

Nomenclature

CAS number: 480-64-8
2,4-Dihydroxy-6-methylbenzoic acid; 6-methyl-β-resorcylic acid; 4,6-dihydroxy-o-toluic acid; 2,4-dihydroxy-6-methylbenzenecarboxylic acid; orcinolcarboxylic acid.
C8H8O4; mol wt 168.15.
C 57.14%, H 4.80%, O 38.06%.

Description and references

Found in conjugated form or in depside form in Roccella and Lecanora lichens, postulated to arise by autocondensation of acetoacetic acid. Isoln from the fungus Chaetomium cochliodes: Mosback, Z. Naturforsch. 14B, 69 (1959). Synthesis: Sonn, Ber. 61, 926 (1928); Kloss, Clayton, J. Org. Chem. 30, 3566 (1965).

Chemical structure

Properties

Needles from acetone, mp 176° (effervescence). pK (25°) 3.90. uv max (0.1N HCl): 214, 260, 296 nm; in 0.1N NaOH: 272 nm. Sol in water, alcohol, glycerol. Soly in ether at 20° = 15.7%. Slightly sol in benzene.

Derivative

Monohydrate.

Properties

Needles from water, mp 186-189°.

Derivative

Methyl ester.
C9H10O4; mol wt 182.17.
C 59.34%, H 5.53%, O 35.13%.

Properties

Crystals, mp 140°.

Derivative

Ethyl ester.
C10H12O4; mol wt 196.20.
C 61.22%, H 6.16%, O 32.62%.

Properties

Crystals, mp 132°.