|
Methyl
(R)-gamma-cyclogeranate - more common than
(S)-enantiomer, camphoraceous, corky,
cellar
= methyl
(1R)-2,2-dimethyl-6-methylenecyclohexanecarboxylate
The racemic
methyl gamma-cyclogeranate is described as:
develops floral, rosy notes possessing a
damascone type nuance, and a spicy-saffron side.
Its odor note also possesses an
herbaceous-thujonic connotation. When compared
to its methyl alpha-cyclogeranate isomer, the
racemic methyl gamma-cyclogeranate is shown to
possess a more floral and rosy note, and
particularly more damascone-like than the note
characterizing the alpha-isomer which is rather
more herbaceous, camomile,
camphoraceous-aromatic and not at all
damascone-like. Furthermore, the odor note of
methyl gamma-cyclogeranate is much more powerful
than that of its alpha-isomer, a rather
unexpected result if one considers that the
opposite behavior is observed between alpha and
gamma-damascones (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, 1–42 (2003);
Charles Fehr & Jose Galindo, Alicyclic
esters and their use as perfuming ingredients,
United States Patent 5,015,625 (May 14,
1991)
|
-gamma-cyclogeranate.gif)
-gamma-cyclogeranate.gif)