Title: Terreic Acid
CAS Registry Number: 121-40-4
CAS Name: (1R)-3-Hydroxy-4-methyl-7-oxabicyclo[4.1.0]hept-3-ene-2,5-dione
Additional Names: 2-hydroxy-3-methyl-1,4-benzoquinone 5,6-epoxide; 5,6-epoxy-3-hydroxy-p-toluquinone
Molecular Formula: C7H6O4
Molecular Weight: 154.12
Percent Composition: C 54.55%, H 3.92%, O 41.52%
Literature References: Antibiotic metabolite produced by the mold Aspergillus terreus; naturally occurring as the (-)-form: Wilkins, Harris, Br. J. Exp. Pathol. 23, 166 (1942); Abraham, Florey, in H. W. Florey et al., Antibiotics vol. I (Oxford Univ. Press, New York, 1949) p 337; Kaplan et al., Antibiot. Chemother. 4, 746 (1954). Structure: Sheehan et al., J. Am. Chem. Soc. 80, 5536 (1958). Synthesis of the racemate: Rashid, Read, J. Chem. Soc. C 1967, 1323. Alternate synthesis and resolution of isomers: Sheehan, Lo, J. Med. Chem. 17, 371 (1974). Improved synthesis: A. Enhsen et al., J. Org. Chem. 55, 1177 (1990).
Properties: Pale yellow plates from benzene or hexane. Easily sublimed in vacuo. mp 127-127.5°. Rotation varies considerably with the solvent: [a]D22 -16.6° (chloroform); [a]D22 -28.6° (methanol-benzene 1:1); [a]D22 +74.3° (pH 7 phosphate buffer). uv max (ethanol): 214, 316 nm (log e 4.03, 3.88). Enol-type acid, pKa 4.5. Slightly sol in water. Soluble in ether, lower alcohols, acetone, hot cyclohexane. Moderately stable to mineral acid, but dec rapidly in alkaline soln.
Melting point: mp 127-127.5°
pKa: pKa 4.5
Optical Rotation: [a]D22 -16.6° (chloroform); [a]D22 -28.6° (methanol-benzene 1:1); [a]D22 +74.3° (pH 7 phosphate buffer)
Absorption maximum: uv max (ethanol): 214, 316 nm (log e 4.03, 3.88) |