Trimethylcyclohexenyl compounds and aroma compositions containing the same

Novel trimethylcyclohexenyl compounds of the 1,3,3-trimethyl-1-cyclohexene type having a 3-hydroxy-3-lower alkylpropionyl group at the 6-position of the cyclohexene are provided. These trimethylcyclohexenyl compounds have a floral note reminiscent of a variety of odors. There are also provided aroma compositions containing these compounds.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to trimethylcyclohexenyl compounds of the 
1,3,3-trimethylcyclohexene type having a 3-hydroxy-3-lower alkylpropionyl 
group at the 6-position of the cyclohexene and aroma compositions 
containing the same. 
2. Description of the Prior Art 
It is known that cycloaliphatic crotonoyl compounds such as 
2,4,4-trimethyl-1-trans-crotonoyl-2-cyclohexene bear and yield a natural 
fruity odor and increase wine-like and fresh flower-like nuances (cf. U.S. 
Pat. No. 3,822,315). 
It is also known that 2,6,6-trimethyl-1-crotonoyl-1-cyclohexene, 
2,6,6-trimethyl-1-crotonoyl-2-cyclohexene and the like have fruity, 
herb-like, winy, woody, floral or waxy flavor notes and, in some 
instances, impart a red berry-like flavor to products, and further enhance 
the taste and flavor of such products as honey and wine (cf. U.S. Pat. No. 
3,928,456). 
An object of the present invention is to provide novel 
trimethylcyclohexenyl compounds that are particular and different in odor 
from known cyclohexenyl compounds such as mentioned above. 
Another object of the invention is to provide the use of said novel 
trimethylcyclohexenyl compounds having particular odor as ingredients of 
compounded perfumes or food flavoring agents. 
These objects as well as other objects and advantages of the invention will 
become apparent to those skilled in the art from the following detailed 
description. 
SUMMARY OF THE INVENTION 
In accordance with the present invention, there are provided 
trimethylcylohexenyl compounds of general formula (I) 
##STR1## 
wherein R is a lower alkyl group. 
The invention also provides aroma compositions containing a 
trimethylcyclohexenyl compound of the above formula (I). 
DETAILED DESCRIPTION OF THE INVENTION 
In the above formula, R is a lower alkyl group such as methyl, ethyl, 
propyl or butyl. As will be described later herein, a methyl group is a 
particularly preferred species of R from the viewpoint of odoriferous 
characteristics owned by the trimethylcyclohexenyl compounds of general 
formula (I). 
The present inventors synthesized a large number of cyclohexenyl compounds 
and investigated their characteristics as aroma chemicals and, as a 
result, found that trimethylcyclohexenyl compounds represented by the 
above general formula (I) are odoriferous compounds which have a slight 
camphor-like odor and floral odor with a sweet fruity note and are 
reminiscent of a cedar- or ionone-like woody note as well as a warm tabac 
note and a musk- or ambergris-like animal note and that said compounds are 
satisfactory from both the diffusion and retention viewpoints and have 
favorable properties rendering them compatible with a variety of fragrance 
materials. 
The trimethylcyclohexenyl compounds of general formula (I) are superior in 
diffusion and retention to the prior art cyclohexenyl compounds as 
mentioned above. 
The trimethylcyclohexenyl compounds according to the invention can be added 
to perfume, fragrance compositions in their pure forms or they can be 
added to mixtures of materials in fragrance-imparting compositions to 
provide a desired fragrance character to a finished perfume material. The 
perfume, fragrance compositions obtained according to the invention are 
suitble in a wide variety of perfumed articles and can also be used to 
enhance, modify or reinforce natural fragrance materials. It will thus be 
appreciated that the trimethylcyclohexenyl compounds according to the 
invention each are useful as olfactory agents and fragrances. 
The term "perfume, fragrance composition" is used herein to mean a mixture 
of compounds, including, for example, natural oils, synthetic oils, 
alcohols, aldehydes, ketones, esters, lactones, and frequently 
hydrocarbons which are admixed so that the combined odors of the 
individual components produce a pleasant or desired fragrance. Such 
perfume, fragrance compositions usually contain (a) the main note or the 
bouquet or foundation-stone of the composition, (b) modifiers which round 
off and accompany the main note, (c) fixatives which include odorous 
substances which lend a particular note to the composition throughout all 
stages of evaporation, and substances which retard evaporation, and (d) 
top notes which are usually low-boiling fresh-smelling materials. Such 
perfume, fragrance compositions of the invention can be used in 
conjunction with carriers, vehicles, solvents, dispersants, emulsifiers, 
surface-active agents, aerosol propellants and the like. 
In perfume, fragrance compositions, the individual components contribute 
their particular olfactory characteristics, but the overall effect of the 
perfume, fragrance composition will be the sum of the effect of each 
ingredient. Thus, the trimethylcyclohexenyl compounds according to the 
invention can be used alone or in combination to alter the aroma 
characteristics of a perfume, fragrance composition, for example, by 
highlighting or moderating the olfactory reaction contributed by another 
ingredient of the composition. 
The perfume, fragrance composition according to the invention contains an 
olfactorily sensible amount of the trimethylcyclohexenyl compounds as 
represented by general formula (I). The proportion of the 
trimethylcyclohexenyl compounds as represented by general formula (I) in 
the total composition may vary according to the intended use of the 
composition; for example, it may range from about 0.005 weight percent to 
95 weight percent. The perfume, fragrance composition of the invention can 
be used in a large variety of ways. For example, it can be used as or in 
soaps; space deodorants; perfumes and eau de cologne; cosmetic 
preparations such as lotions, creams, etc.; bath supplies such as bath 
oil, bath salts, etc.; hair preparations such as hair tonics, pomades, 
hair liquids, hair creams, stick pomades, shampoos, rinses, etc.; 
cleansers; detergents, etc. In addition, the perfume, fragrance 
composition can also be used for scenting such substrates as textile 
fibers and fabrics, paper products and so on. 
Compare further our pending Japanese Patent Application No. 83653/82, filed 
on May 17, 1982, published on Nov. 24, 1983, hereby expressly incorporated 
by reference and relied upon. 
The trimethylcyclohexenyl compounds according to the invention are also 
useful as ingredients for the preparation of artificial flavors and as 
flavor additives in foodstuffs, animal feeds, beverages, pharmaceutical 
preparations and tobacco products. The term "foodstuff" is used in this 
specification in its broadest sense and is meant to include also products 
such as coffee, tea and cocoa. 
When the trimethylcyclohexenyl compounds according to the invention are 
used as flavoring agents or additives for modifying the organoleptic 
properties of foodstuffs, animal feeds, beverages, pharmaceutical 
preparations and tobacco products, said trimethylcyclohexenyl compounds 
can be used in proportions which, again, vary within wide limits. 
Interesting flavoring effects, for instance, can be achieved by using the 
trimethylcyclohexenyl compounds according to the invention in proportions 
from 0.1 to 10 ppm based on the weight of the products to be flavored. 
However, these proportions can be increased beyond 10 ppm up to about 100 
ppm in order to achieve special flavoring effects. In the preparation of 
flavoring compositions by admixing the trimethylcyclohexenyl compounds to 
other aromatics, the said compounds can be used, for example, in 
proportions of about 0.1% to about 15% of the total weight of the 
flavoring composition. In many cases average proportions of about 1 to 10% 
by weight will give the desired results. 
The trimethylcyclohexenyl compounds of general formula (I) can be produced 
easily, for example, via the route given below starting with the per se 
known 1-acetyl-2,4,4-trimethyl-2-cyclohexene. 
##STR2## 
In the above formulas, X is a halogen atom and R is as defined above 
relative to general formula (I). 
Thus, 1-acetyl-2,4,4-trimethyl-2-cyclohexene and an alkyl Grignard reagent 
such as ethylmagnesium chloride, ethylmagnesium bromide, etc. are reacted 
in a solvent such as diethyl ether, tetrahydrofuran, etc. at a temperature 
of -20.degree. C. to 35.degree. C. The thus-obtained organometallic 
compound (II) is reacted with an aldehyde of general formula (III) in a 
solvent such as benzene, toluene, xylene, etc. at a temperature of 
-10.degree. C. to 15.degree. C., and the reaction product is hydrolyzed 
under weakly acidic conditions produced by the presence of diluted 
hydrochloric acid, ammonium chloride or the like to give a 
trimethylcyclohexenyl compound of general formula (I).

The following examples are given to merely illustrate the invention in 
further detail and should by no means be construed as limiting the scope 
of the invention. 
EXAMPLE 1 
Synthesis of 1-(3-hydroxybutyryl)-2,4,4-trimethyl-2-cyclohexene 
A solution of 18.6 g of N-methylaniline in 57 ml of benzene was added 
dropwise to a solution of Grignard reagent in diethylether, said Grignard 
reagent being prepared from 4.6 g of magnesium and 22.8 g of ethyl 
bromide, at a temperature of 0.degree. C. to 5.degree. C., and the mixture 
was stirred at 15.degree. C. for 10 minutes. At the same temperature, a 
solution of 33.2 g of 1-acetyl-2,4,4-trimethyl-2-cyclohexene in 29 ml of 
benzene was added dropwise to the above-obtained solution. The mixture was 
stirred at room temperature for 30 minutes and then cooled to around 
-10.degree. C. and a solution of 5.9 g of acetaldehyde in 14.3 ml of 
benzene was added dropwise thereto at a temperature of -13.degree. C. to 
-10.degree. C., followed by stirring at a temperature of -10.degree. C. to 
-5.degree. C. for 1 hour. To this mixture was added aqueous saturated 
ammonium chloride and the resulting mixture was extracted with three 
100-ml portions of benzene. The benzene extract was washed with diluted 
hydrochloric acid and then washed thoroughly with water for neutralization 
and dried over anhydrous sodium sulfate. The benzene was removed from the 
extract using an evaporator and the residue was distilled under reduced 
pressure to give 17.8 g of a colorless to light-yellow liquid as the 
distillate fraction boiling at 85.degree.-89.degree. C./1-2 mm Hg. Based 
on the following analytical data, the product was identified as 
1-(3-hydroxybutyryl)-2,4,4-trimethyl-2-cyclohexene. 
##STR3## 
FD-Mass: m/e 210 
IR (cm.sup.-1): 3450, 2980, 2850, 1710, 1450, 1360 
H.sup.1 -NMR (.delta..sub.ppm .sup.CDCl.sbsp.3): 0.92, 0.97 (each s, 6H, 
##STR4## 
1.15 (d, 3H, 
##STR5## 
1.56 (s, 3H, 
##STR6## 
2.4-2.8 (m, 2H, 
##STR7## 
2.97 (t, 1H, 
##STR8## 
3.9-4.4 (m, 1H, 
##STR9## 
5.35 (s, 1H, 
##STR10## 
EXAMPLE 2 
Synthesis of 1-(3-hydroxypentanoyl)-2,4,4-trimethyl-2-cyclohexene 
The procedure of Example 1 was followed except that 7.8 g of 
propionaldehyde was used in lieu of 5.9 g of acetaldehyde, followed by 
distillation under reduced pressure to give 18.2 g of a colorless to 
light-yellow liquid as the distillate fraction boiling at 
83.degree.-98.degree. C./0.5-2 mm Hg. Based on the following analytical 
data, the product was identified as 
1-(3-hydroxypentanoyl)-2,4,4-trimethyl-2-cyclohexene. 
##STR11## 
FD-Mass: m/e 224 
IR (cm.sup.-1): 3450, 2950, 2850, 1700, 1450, 1380, 1360 
H.sup.1 -NMR (.delta..sub.ppm.sup.CDCl.sbsp.3): 
1.55 (s, 3H, 
##STR12## 
2.4-2.7 (m, 2H, 
##STR13## 
2.98 (t, 1H, 
##STR14## 
3.8-4.1 (m, 1H, 
##STR15## 
5.37 (s, 1H, 
##STR16## 
EXAMPLE 3 
Synthesis of 1-(3-hydroxy-4-methylpentanoyl)-2,4,4-trimethyl-2-cyclohexene 
The procedure of Example 1 was followed except that 9.6 g of 
isobutylaldehyde was used in lieu of 5.9 g of acetaldehyde, followed by 
distillation under reduced pressure to give 19.0 g of a colorless to 
light-yellow liquid as the distillate fraction boiling at 
103.degree.-108.degree. C./0.5 mm Hg. Based on the following analytical 
data, the product was identified as 
1-(3-hydroxy-4-methylpentanoyl)-2,4,4-trimethyl-2-cyclohexene. 
##STR17## 
FD-Mass: m/e 238 
IR (cm.sup.-1): 3450, 2960, 2840, 1710, 1450, 1360 
H.sup.1 -NMR (.delta..sub.ppm .sup.CCl.sbsp.4): 
1.53 (s, 3H, 
##STR18## 
2.35-2.50 (m, 2H, 
##STR19## 
2.84 (t, 1H, 
##STR20## 
3.50-3.80 (m, 1H, 
##STR21## 
5.27 (s, 1H, 
##STR22## 
EXAMPLE 4 
Perfume Composition of the Rose Type 
A perfume composition having a rose-like note was prepared according to the 
following formula. 
______________________________________ 
Parts by weight 
______________________________________ 
Phenylethyl alcohol 300 
Geraniol 150 
Citronellol 150 
Linalool 60 
Guaiac wood oil 40 
Eugenol 10 
Benzyl acetate 70 
Phenylacetaldehyde 5 
Citronellyl formate 3 
Geranyl acetate 10 
Cinnamic alcohol 50 
Geranium oil 30 
Aldehyde C-11 (*10% solution in DEP) 
1 
Aldehyde C-10 (*10% solution in DEP) 
1 
Nerolidol 30 
Rose absolute 10 
1-(3-Hydroxybutyryl)-2,4,4-tri- 
80 
methyl-2-cyclohexene 1000 
______________________________________ 
*DEP stands for diethyl phthalate. 
The use of 80 parts by weight of 
1-(3-hydroxypentanoyl)-2,4,4-trimethyl-2-cyclohexene or 
1-(3-hydroxy-4-methylpentanoyl)-2,4,4-trimethyl-2-cyclohexene in place of 
80 parts by weight of 1-(3-hydroxybutyryl)-2,4,4-trimethyl-2-cyclohexene 
in the above formula also gave a perfume composition having a rose-like 
note. 
EXAMPLE 5 
Perfume Composition of the Lilac Type 
A perfume composition having a lilac-like note was prepared according to 
the following formula. 
______________________________________ 
Parts by weight 
______________________________________ 
Terpineol 150 
Hydroxycitronellal 120 
Phenylethyl alcohol 130 
Heliotropin 80 
Cinnamic alcohol 50 
Nerol 20 
Vanillon 20 
Linalool 80 
Geraniol 30 
Benzyl acetate 50 
Anisaldehyde 40 
Ylang-ylang oil 60 
Isoeugenol 20 
Styrax oil 10 
Petitgrain oil 10 
Hydrocinnamic aldehyde 5 
Jasmin absolute 5 
Aldehyde C-10 (*10% solution in DEP) 
5 
Farnesol 30 
Indole (*10% solution in DEP) 
5 
1-(3-Hydroxybutyryl)-2,4,4-tri- 
80 
methyl-2-cyclohexene 1000 
______________________________________ 
*DEP stands for diethyl phthalate. 
The use of 80 parts by weight of 
1-(3-hydroxypentanoyl)-2,4,4-trimethyl-2-cyclohexene or 
1-(3-hydroxy-4-methylpentanoyl)-2,4,4-trimethyl-2-cyclohexene in place of 
80 parts by weight of 1-(3-hydroxybutyryl)-2,4,4-trimethyl-2-cyclohexene 
in the above formula also gave a perfume composition having a lilac-like 
note. 
EXAMPLE 6 
Perfume Composition of the Violet Type 
A perfume composition having a violet-like note was prepared according to 
the following formula. 
______________________________________ 
Parts by weight 
______________________________________ 
.alpha.-Ionone 300 
Methylionone 30 
Benzyl acetate 80 
Phenylethyl alcohol 
150 
Linalool 30 
Geraniol 30 
Ylang-ylang oil 50 
Violet leaf oil 5 
Vetiver oil 20 
Sandalwood oil 30 
Labdanum oil 5 
Hydroxycitronellal 50 
Heliotropin 30 
Linalyl acetate 40 
Musk ambrette 20 
Jasmin absolute 50 
1-(3-Hydroxybutyryl)-2,4,4-tri- 
80 
methyl-2-cyclohexene 
1000 
______________________________________ 
The use of 80 parts by weight of 
1-(3-hydroxypentanoyl)-2,4,4-trimethyl-2-cyclohexene or 
1-(3-hydroxy-4-methylpentanoyl)-2,4,4-trimethyl-2-cyclohexene in place of 
80 parts by weight of 1-(3-hydroxybutyryl)-2,4,4-trimethyl-2-cyclohexene 
in the above formula also gave a perfume composition having a violet-like 
note. 
EXAMPLE 7 
Perfume Composition of the Jasmin Type 
A perfume composition (base) having a jasmin-like note was prepared 
according to the following formula. 
______________________________________ 
Parts by weight 
______________________________________ 
Benzyl acetate 30 
Hexylcinnamic alcohol 
20 
Ylang-ylang oil 5 
Phenylethyl alcohol 
8 
Linalool 5 
Methylionone 5 
Jasmin absolute 3 
Hydroxycitronellal 8 
Linalyl acetate 3 
Nerol 2 
Cinnamic alcohol 3 
Indole 1 
Musk ambrette 2 
1-(3-Hydroxybutyryl)-2,4,4-tri- 
5 
methyl-2-cyclohexene 
100 
______________________________________ 
The use of 5 parts by weight of 
1-(3-hydroxypentanoyl)-2,4,4-trimethyl-2-cyclohexene or 
1-(3-hydroxy-4-methylpentanoyl)-2,4,4-trimethyl-2-cyclohexene in place of 
5 parts by weight of 1-(3-hydroxybutyryl)-2,4,4-trimethyl-2-cyclohexene in 
the above formula also gave a perfume composition having a jasmin-like 
note. 
EXAMPLE 8 
Perfume Composition of the Muguet Type 
A perfume composition (base) having a muguet-like note was prepared 
according to the following formula. 
______________________________________ 
Parts by weight 
______________________________________ 
Hydroxycitronellal 35 
Linalool 10 
.alpha.-Terpineol 10 
Phenylethyl alcohol 
5 
Ylang-ylang oil 5 
Bergamot oil 3 
Citronellol 8 
Benzyl salicylate 5 
Heliotropin 3 
Coumarin 3 
Musk tinc. 5 
1-(3-Hydroxybutyryl)-2,4,4-tri- 
8 
methyl-2-cyclohexene 
100 
______________________________________ 
The use of 8 parts by weight of 
1-(3-hydroxypentanoyl)-2,4,4-trimethyl-2-cyclohexene or 
1-(3-hydroxy-4-methylpentanoyl)-2,4,4-trimethyl-2-cyclohexene in place of 
8 parts by weight of 1-(3-hydroxybutyryl)-2,4,4-trimethyl-2-cyclohexene in 
the above formula also gave a perfume composition having a muguet-like 
note. 
EXAMPLE 9 
"Tutti-Frutti" Flavoring Composition 
A "Tutti-Frutti" flavoring composition for food use was prepared according 
to the following formula. 
______________________________________ 
Parts by weight 
______________________________________ 
Vanillin 20 
Allyl caproate 10 
Citral 20 
Amyl butyrate 35 
Orange oil 45 
Ethyl butyrate 75 
Ethyl acetate 185 
Amyl acetate 185 
Lemon oil 415 
1-(3-Hydroxybutyryl)-2,4,4-tri- 
10 
methyl-2-cyclohexene 
1000 
______________________________________ 
The use of 10 parts by weight of 
1-(3-hydroxypentanoyl)-2,4,4-trimethyl-2-cyclohexene or 
1-(3-hydroxy-4-methylpentanoyl)-2,4,4-trimethyl-2-cyclohexene in place of 
10 parts by weight of 1-(3-hydroxybutyryl)-2,4,4-trimethyl-2-cyclohexene 
in the above formula also gave a "Tutti-Frutti" flavoring composition for 
food use.