Ethyl
(R)-gamma-cyclogeranate - less fruity, aromatic,
rosemary, less powerful than the
(S)-enantiomer
= ethyl
(1R)-2,2-dimethyl-6-methylenecyclohexanecarboxylate
The racemic
ethyl gamma-cyclogeranate is described as:
develops a floral, rosy odor, with a less
pronounced damascone character than that of its
methyl ester homologue, but more metallic than
the latter. On the other hand, the
thujonic-absinthe side of the note is much more
pronounced in the ethyl ester odor. When
compared to its methyl alpha-cyclogeranate
isomer, the racemic ethyl gamma-cyclogeranate is
shown to possesses a more camphoraceous, fruity,
damascone-like and elegant odor note than that
methyl alpha-cyclogeranate (US Patent No.
5,015,625).
Ref: Charles
Fehr & Jose Galindo, Syntheses of the
Enantiomers of gamma-Cyclogeranic Acid,
gamma-Cyclocitral, and gamma-Damascone:
Enantioselective Protonation of Enolates,
Helv.Chim.Acta 1995, 78: 539-552; Elisabetta
Brenna, Claudio Fuganti and Stefano Serra,
Enantioselective perception of chiral odorants,
Tetrahedron: Asymmetry, 14, 142 (2003);
Charles Fehr & Jose Galindo, Alicyclic
esters and their use as perfuming ingredients,
United States Patent 5,015,625 (May 14,
1991)
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