Perfume compositions – Perfume compositions – Ring containing active ingredient
Reexamination Certificate
1999-05-07
2001-01-23
Padmanabhan, Sreeni (Department: 1621)
Perfume compositions
Perfume compositions
Ring containing active ingredient
C512S022000, C512S023000, C512S025000, C560S231000, C560S259000, C568S377000, C568S378000, C549S369000, C549S430000
Reexamination Certificate
active
06177400
ABSTRACT:
BRIEF SUMMARY OF THE INVENTION
The present invention relates to the field of perfumery. It relates, more particularly, to compounds derived from the 4,4,6-trimethylcyclohexane skeleton and being represented by the structure according to the general formula (I)
in which formula the dotted lines indicate a single or a double bond which may optionally be present in the molecule, n and m are 0 or 1, R
1
is hydrogen or an acyl group —C(O)R
3
, R
3
being a linear or branched alkyl or alkylene group from C
1
to C
8
, or a substituted or unsubstituted phenyl group, the oxygen atom being bound to the adjacent &agr;-carbon atom by a double bond in the case where n is 0 and by a single bond in the case where n is 1, R
2
is hydrogen or a linear or branched alkyl, alkenyl or alkoxy group from C
1
to C
8
, or R
2
is an alkenoxy group which is linked to the group R
1
to form a 1,3-dioxolane cycle having 5 to 7 ring members.
BACKGROUND OF THE INVENTION
The compounds according to the above formula (I) form a novel class of fragrant molecules the use of which has never been proposed in perfumery. In fact, there exist in this field classes of compounds derived from a cyclohexane ring which carries three methyl substituents, but with a different substitution pattern, as shown in formula (II), in which the dotted lines indicate a double bond which may optionally be present in the C
6
-ring and R is an organic rest carrying, for example, a keto function
DETAILED DESCRIPTION OF THE INVENTION
As is clear from a comparison of the two formulae (I) and (II), the compounds known from the prior art are 2,6,6-trimethyl-substituted, which is in contrast to the 4,6,6-trimethyl substitution of the compounds according to the present invention. Well-known examples for the compounds according to formula (II) are damascones and damascenone, in which case R is a —(O)C—CH═CH—CH
3
group and the ring carries one double bond in the 1-, 2- or 3-position for damascones, and two double bonds in the 1- and 3-position for damascenone.
To our great surprise, and in spite of the structural ressemblance of the compounds known in the art with the class of molecules according to the present invention and outlined in the above formula (I), we were the first to establish the perfumistic value of these said compounds.
The base molecule which serves as starting product for the synthesis of the class of compounds according to formula (I) is 4,6,6-trimethyl-1,3-cyclohexadiene-1-carbaldehyde, which has for the first time been described by A. F. Thomas et al. in Helv. Chim. Acta 59 (1976), p. 2261-7. As is shown in the scheme (1) below, this compound is then converted into the desired products by the introduction of functional groups, eventually after hydrogenation of one or both of the carbon-carbon double bonds in the C
6
-ring. As a consequence, the dotted lines in the molecules shown in the scheme below indicate these optionally present double bonds. The reference to the synthesis of the respective compounds in the scheme below is not limiting, refering only to examples for the preparation of the respective class of compounds. The symbols R
4
-R
7
in the scheme (1) will be defined further below, in the paragraphs refering to the respective classes of compounds. The classes of molecules shown in scheme (1) are preferred according to the present invention.
a) reduction (e.g. NaBH
4
, LiAlH
4
)
b) esterification (e.g. carboxylic acid, anhydride or halide)
c) acetalization (e.g. divalent alcohol)
d) Grignard reagent/hydrolysis; then oxidation [e.g. manganese dioxide, pyridinium dichromate (PDC) or pyridinium chlorochromate (PCC)]
The mentioned carbaldehydes (III) in the above scheme are themselves of perfumistic value. In particular, the 2,2,4-trimethyl-1-cyclohexanecarbaldehyde shows a nice, fresh, aldehyde- and thuyone-like odor with a green connotation reminiscent of Zestover (2,4-dimethyl-3-cyclohexene-1-carbaldehyde; origin: Firmenich SA) and 3,5,5-trimethylhexanal.
The alcohols (IV), obtainable from the above carbaldehydes by reduction of the carbonyl function, show olfactory notes which are different from those of the latter, with the aldehyde note being totally absent. 4,6,6-Trimethyl-1,3-cyclohexadiene-1-methanol has a balsamic-woody note with an incense type connotation being present, somewhat typical of the odor inside a church. The corresponding saturated alcohol, i.e. 2,2,4-trimethyl-1-cyclohexanemethanol, has an odor composed of green and earthy, borneol-camphoraceous-pinanol notes, with a minty connotation being also found.
Another interesting group of compounds, from an olfactory point of view, are the acetals (VI), obtainable from the above-mentioned aldehydes (III) by acetalization. In the above formula (VI), R
5
and R
6
can be identical or different and are hydrogen or a linear or branched alkyl group from C
1
to C
6
, and n is an integer from 1 to 3. They show woody, fruity and spicy odors, the most interesting compound being 4-methyl-2-(4,6,6-trimethyl-1-cyclohexen-1-yl)-1,3-dioxolan. The odor of this latter is of the woody-camphoraceous type with a strong liquorice undernote, pleasant and appreciated by perfumers.
The esters according to the formula (V) in the above scheme, in which R
4
is a linear or branched alkyl group from C
1
to C
8
or a substituted or unsubstituted phenyl group, have odors of the floral type which are accompanied by undernotes which vary depending on the structure. Amongst the said esters, one preferred compound is (4,4,6-trimethyl-1,3-cyclohexadien-1-yl)methyl isobutyrate which has a complex odor profile, being composed of notes reminiscent of Isopentyrate (1,3-dimethyl-3-butenyl isobutyrate; origin: Firmenich SA), i.e. fruity-floral with a camomile connotation. There are further perceived notes which are typical of damascones, butyrates and carbinols, with a base note of Estragol® (1-allyl-4-methoxybenzene; origin: Givaudan-Roure SA, Vernier, Switzerland). Two other preferred esters are (4,6,6-trimethyl-1-cyclohexen-1-yl)methyl acetate and —butanoate. The acetate has a jasmine note with fruity amylic connotations, whereas the odor of the butanoate is remiscent of orris, with a ionone undernote. Finally, another preferred ester is (2,2,4-trimethyl-1-cyclohexyl)methyl acetate which shows an odor profil reminiscent of Dorysil (4-tert-butyl-1-cyclohexyl acetate; origin: Firmenich SA), i.e. of the fruity-jasmine type, and methylionones, with a woody-hazelnut connotation.
The &agr;,&bgr;-unsaturated ketones according to the general formula (VII) in which R
7
is a linear or branched alkyl or alkylene group from C
1
to C
4
are compounds of perfumistic importance. They are structurally related to the well-known damascones or damascenones, but can olfactively be clearly distinguished from these, also due to various pleasant and appreciated undernotes which are not known in combination with the damascone, respectively damascenone-type note which is always found in the molecules according to formula (VII). In general, the damascone-damascenone type odor is accompanied by fruity undernotes. The synthesis and the odor of the compounds according to formula (VII) in which R
7
is a methyl group and which has one double bond in position 3 of the cycle is described by V. M. Andreev et al in Hydrolysis and Wood Chem. 1993, p 23-25.
The preferred type of compounds within the group described by the general formula (VII) are the &agr;,&bgr;-unsaturated ketones which obey to the general formulae (VIII) and (IX)
wherein R
7
is a linear or branched alkyl or alkenyl group from C
1
to C
4
, and which may be in the form of the isomer of the (E) or (Z) configuration, or a mixture of the two.
The compounds of this type are not described in the chemical literature, and the difference between the said compounds and the already mentioned damascones and, respectively damascenones, lies in the position of the methyl substituent at the C
6
-ring [position 2 for the damascones and damascenones, position 4 for the compounds according to the invention] The damascones and damasce
Giersch Wolfgang Klaus
Mimoun Hubert
Firmenich SA
Padmanabhan Sreeni
Pennie & Edmonds LLP
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