6470. Nepetalactone

Nomenclature

CAS number: 490-10-8
5,6,7,7a-Tetrahydro-4,7-dimethylcyclopenta[c]pyran-1-(4aH)-one.
C10H14O2; mol wt 166.22.
C 72.26%, H 8.49%, O 19.25%.

Description and references

The first fully characterized methylcyclopentane monoterpenoid. Isolated from the volatile oil of catnip produced by Nepeta cataria L., Labiatae: S. M. McElvain et al., J. Am. Chem. Soc. 63, 1558 (1941); J. Meinwald, ibid. 76, 4571 (1954). First believed to be a single entity, it was later shown to be a mixture of the cis-trans and trans-cis isomers, the cis-trans isomer comprising 70-99% of the oil. Structure: S. M. McElvain, E. J. Eisenbraun, J. Am. Chem. Soc. 77, 1599 (1955). Configuration of the cis-trans and trans-cis isomers: R. B. Bates et al., ibid. 80, 3420 (1958). Separation and properties: R. B. Bates, C. W. Siegel, Experientia 19, 564 (1963). Biosynthesis: F. E. Regnier et al., Phytochemistry 7, 221 (1968). Metabolism in cats: G. R. Waller et al., Science 164, 1281 (1969). Behavioral and toxicological study: J. W. Harney et al., Lloydia 41, 367 (1978). Structural study of isomeric nepetalactones: E. J. Eisenbraun et al., J. Org. Chem. 45, 3811 (1980).

Chemical structure

Properties

Oil. Odor very attractive to cats. d425 1.0663. bp0.05 71-72°. [α]D23+3.6°. nD25 1.4859. Soluble in ether, carbon tetrachloride. When shaken with 10% NaOH yields nepetalic acid, crystals, mp 74°, [α]D30 +47.6° (chloroform).

Derivative

cis-trans-Form.

Nomenclature

CAS number: 21651-62-7
2-(2-Hydroxy-1-methylethenyl)-5-methylcyclopentanecarboxylic acid delta lactone.

Properties

Oil, [α]D21 +3.7° (c = 27 in chloroform). [α]D27.5 +11.11° (chloroform). nD25 1.4878.

Derivative

trans-cis-Form.

Properties

mp 37-39°. [α]D21 -24.4° (c = 6.15 in chloroform) (Eisenbraun); also reported as [α]D27.5 +21.9° (chloroform) (Bates, Siegel). nD25 1.4878.