Abstract:
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.

Description:
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 &#34;perfume, fragrance composition&#34; 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 &#34;foodstuff&#34; 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° C. to 35° 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° C. to 15° 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° C. to 5° C., and the mixture was stirred at 15° 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° 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° C. to -10° C., followed by stirring at a temperature of -10° C. to -5° 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°-89° 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 -1 ): 3450, 2980, 2850, 1710, 1450, 1360 
     H 1  -NMR (δ ppm   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°-98° 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 -1 ): 3450, 2950, 2850, 1700, 1450, 1380, 1360 
     H 1  -NMR (δ ppm   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°-108° 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 -1 ): 3450, 2960, 2840, 1710, 1450, 1360 
     H 1  -NMR (δ ppm   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    300Geraniol               150Citronellol            150Linalool               60Guaiac wood oil        40Eugenol                10Benzyl acetate         70Phenylacetaldehyde     5Citronellyl formate    3Geranyl acetate        10Cinnamic alcohol       50Geranium oil           30Aldehyde C-11 (*10% solution in DEP)                  1Aldehyde C-10 (*10% solution in DEP)                  1Nerolidol              30Rose absolute          101-(3-Hydroxybutyryl)-2,4,4-tri-                  80methyl-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              150Hydroxycitronellal     120Phenylethyl alcohol    130Heliotropin            80Cinnamic alcohol       50Nerol                  20Vanillon               20Linalool               80Geraniol               30Benzyl acetate         50Anisaldehyde           40Ylang-ylang oil        60Isoeugenol             20Styrax oil             10Petitgrain oil         10Hydrocinnamic aldehyde 5Jasmin absolute        5Aldehyde C-10 (*10% solution in DEP)                  5Farnesol               30Indole (*10% solution in DEP)                  51-(3-Hydroxybutyryl)-2,4,4-tri-                  80methyl-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______________________________________α-Ionone     300Methylionone       30Benzyl acetate     80Phenylethyl alcohol              150Linalool           30Geraniol           30Ylang-ylang oil    50Violet leaf oil    5Vetiver oil        20Sandalwood oil     30Labdanum oil       5Hydroxycitronellal 50Heliotropin        30Linalyl acetate    40Musk ambrette      20Jasmin absolute    501-(3-Hydroxybutyryl)-2,4,4-tri-              80methyl-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     30Hexylcinnamic alcohol              20Ylang-ylang oil    5Phenylethyl alcohol              8Linalool           5Methylionone       5Jasmin absolute    3Hydroxycitronellal 8Linalyl acetate    3Nerol              2Cinnamic alcohol   3Indole             1Musk ambrette      21-(3-Hydroxybutyryl)-2,4,4-tri-              5methyl-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 35Linalool           10α-Terpineol  10Phenylethyl alcohol              5Ylang-ylang oil    5Bergamot oil       3Citronellol        8Benzyl salicylate  5Heliotropin        3Coumarin           3Musk tinc.         51-(3-Hydroxybutyryl)-2,4,4-tri-              8methyl-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 
     &#34;Tutti-Frutti&#34; Flavoring Composition 
     A &#34;Tutti-Frutti&#34; flavoring composition for food use was prepared according to the following formula. 
     
         ______________________________________            Parts by weight______________________________________Vanillin           20Allyl caproate     10Citral             20Amyl butyrate      35Orange oil         45Ethyl butyrate     75Ethyl acetate      185Amyl acetate       185Lemon oil          4151-(3-Hydroxybutyryl)-2,4,4-tri-              10methyl-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 &#34;Tutti-Frutti&#34; flavoring composition for food use.