Isobutyrate compound having n-butyryloxy group at α position, fragrance composition and use as fragrance

Abstract

A compound represented by formula (1). In formula (1), R represents a linear, branched, or cyclic alkyl group having 1 to 4 carbon atoms. #imgabs0#

Description

Technical Field

[0001] The present invention relates to an isobutyrate compound having an n-butyryloxy group at the α-position, a perfume composition, and use as a perfume. Background Art

[0002] It is known that some isobutyrates are useful as flavoring agents. For example, Non-Patent Document 1 describes various isobutyrates as primarily used as flavoring agents. Specifically, methyl isobutyrate has a sweet apricot-like aroma, propyl isobutyrate has a rich pineapple-like aroma, butyl isobutyrate has a fresh apple and banana-like aroma, and isoamyl isobutyrate has a sweet apricot and pineapple-like aroma. These are all fruity flavoring agents.

[0003] Patent Document 1 discloses that linear or branched alkyl esters of α-alkoxyisobutyric acid having 4 to 12 carbon atoms are useful as fragrances as isobutyrates having an oxygen bond at the α-position, and describes that n-hexyl α-ethoxyisobutyrate has a lavender-like aroma.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: U.S. Patent No. 3368943

[0007] Non-patent literature

[0008] Non-Patent Document 1: "Synthetic Fragrance Chemistry and Product Knowledge Supplementary Edition", Chemical Industry Daily, 2016, pp. 580-582 Summary of the Invention

[0009] The present invention aims to provide an isobutyrate compound having an n-butyryloxy group at the α-position, which is useful as a fragrance and a fragrance blending material. The present invention also aims to provide a fragrance composition containing the compound as an active ingredient, and the use of the compound as a fragrance.

[0010] The present inventors synthesized various compounds and conducted extensive research on their aromas, and found that a specific ester compound of isobutyric acid having an n-butyryloxy group at the α-position is useful as a fragrance and a fragrance material.

[0011] That is, the present invention is as follows.

[0012] <1> A compound represented by formula (1).

[0013]

[0014] (In formula (1), R represents a linear, branched, or cyclic alkyl group having 1 to 4 carbon atoms.)

[0015] <2> The compound according to <1>, wherein, in formula (1), R is selected from the group consisting of methyl, ethyl, n-propyl, isopropyl, n-butyl, and isobutyl.

[0016] <3> The compound according to <1> or <2>, wherein in formula (1), R is a methyl group.

[0017] <4> The compound according to <1> or <2>, wherein in formula (1), R is an ethyl group.

[0018] <5> The compound according to <1> or <2>, wherein in formula (1), R is n-propyl.

[0019] <6> The compound according to <1> or <2>, wherein in formula (1), R is an isopropyl group.

[0020] <7> The compound according to <1> or <2>, wherein in formula (1), R is n-butyl.

[0021] <8> The compound according to <1> or <2>, wherein in formula (1), R is an isobutyl group.

[0022] <9> A flavor composition comprising the compound according to any one of <1> to <8> as an active ingredient.

[0023] <10> Use of the compound according to any one of <1> to <8> as a fragrance.

[0024] <11> The use according to <10>, wherein the compound according to any one of <3>, <4>, and <6> imparts a damask-like fruity, floral, or woody fragrance.

[0025] The present invention provides an isobutyrate compound having an n-butyryloxy group at the α-position, which is useful as a fragrance and a fragrance material. Furthermore, the present invention provides a fragrance composition containing the compound as an active ingredient and the use of the compound as a fragrance. DETAILED DESCRIPTION

[0026] [Compound represented by formula (1)]

[0027] The compound of the present invention is represented by the following formula (1): Hereinafter, the compound represented by the following formula (1) is also referred to as "isobutyrate of the present invention" or "compound of the present invention."

[0028]

[0029] Here, in formula (1), R represents a linear, branched or cyclic alkyl group having 1 to 4 carbon atoms.

[0030] Specific examples of R include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl (2-methylpropyl), sec-butyl (1-methylpropyl), tert-butyl, cyclopropyl, and cyclobutyl.

[0031] When R has an asymmetric carbon, the compound of the present invention may have only one of the optical isomers generated therefrom, or may be a mixture containing a plurality of optical isomers in any ratio.

[0032] The compound represented by formula (1) is a novel compound.

[0033] The isobutyric acid ester represented by formula (1) of the present invention is useful as a fragrance and a fragrance material, and exhibits floral, green, and fruity aromas.

[0034] It is particularly preferred that R is methyl.

[0035] It is particularly preferred that R is ethyl.

[0036] Particularly preferably, R is n-propyl.

[0037] It is particularly preferred that R is isopropyl.

[0038] Particularly preferably, R is n-butyl.

[0039] It is particularly preferred that R is isobutyl.

[0040] In the present invention, examples of the compound represented by formula (1) include compounds represented by any one of the following formulas (1-1) to (1-10), and particularly preferred compounds are compounds represented by any one of the following formulas (1-1) to (1-6).

[0041]

[0042] In recent years, there has been a growing trend toward greater awareness of the toxicity and environmental impact of chemical substances, and this applies to fragrances and fragrance compositions. Due to factors such as human sensitivity and environmental accumulation, the use of traditional fragrances has been severely restricted, and bans on their use are on the rise. Consequently, the demand for fragrances and fragrance compositions with minimal environmental impact is stronger than ever. Consequently, fragrance ingredients also preferably exhibit excellent biodegradability.

[0043] The compound of the present invention includes compounds having excellent biodegradability. From the viewpoint of biodegradability, R is preferably a group selected from the group consisting of methyl, ethyl, n-propyl, isopropyl, n-butyl, and isobutyl.

[0044] The isobutyrate of the present invention itself has an excellent aroma as described later, and is therefore useful as a fragrance. In addition, fragrances are generally rarely used alone, and are mostly used as blended fragrances (fragrance compositions) that are combined with multiple fragrances according to the purpose. The isobutyrate of the present invention is useful as a fragrance (also referred to as a "blended fragrance material") that is combined with a blended fragrance (fragrance composition). As a fragrance, the compound represented by the above formula (1) can be used alone or in combination of two or more.

[0045] Furthermore, the compound of the present invention may contain a small amount of impurities, by-products, inclusions, etc., within a range that does not impair the effects of the present invention.

[0046] The isobutyric acid ester of the present invention represented by formula (1) has a floral, green, or fruity aroma and is also excellent in diffusibility. Furthermore, the isobutyric acid ester of the present invention represented by any one of formulas (1-1), (1-2), and (1-4) has a damask-like fruity, floral, or woody aroma and is also excellent in diffusibility.

[0047] The isobutyrate of the present invention can be used alone as a fragrance to impart fragrance to various cosmetics, pharmaceuticals including health and hygiene products, daily sundry goods, and foods. Alternatively, the isobutyrate of the present invention can be mixed with other fragrance materials to prepare fragrance compositions (fragrance blends) described below, which can be incorporated into various products to impart fragrance. From the perspective of obtaining the desired fragrance, it is preferred to incorporate the compound of the present invention as a fragrance blend into a fragrance composition, and to incorporate the fragrance composition into the product to impart fragrance.

[0048] [Fragrance composition]

[0049] The fragrance composition (fragrance preparation) of the present invention contains the isobutyrate of the present invention as an active ingredient. It should be noted that there are no particular limitations as long as it contains at least one isobutyrate of the present invention, and it may contain two or more isobutyrates of the present invention.

[0050] The fragrance composition of the present invention may contain the isobutyrate of the present invention as an active ingredient, and other ingredients are not particularly limited. It is preferred that the fragrance composition further contain other blended fragrance materials (hereinafter also referred to as "conventional fragrances").

[0051] The term "fragrance composition (blended fragrance)" refers to a composition that is added to various cosmetics, pharmaceuticals, foods, beverages, etc. to impart fragrance, or a composition that is used as a perfume itself, and may contain additives such as solvents in addition to conventional fragrances as needed.

[0052] The amount of the isobutyrate of the present invention to be incorporated varies depending on the type of the isobutyrate, the type of target aroma, the intensity of the aroma, etc. However, the amount of the isobutyrate of the present invention represented by formula (1) is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, and even more preferably 0.1% by mass or more in the fragrance composition, and is preferably 90% by mass or less, more preferably 70% by mass or less, and even more preferably 50% by mass or less.

[0053] The conventional fragrance is not particularly limited as long as it is a conventionally known fragrance component, and a wide range of fragrances can be used. For example, the following substances can be used alone or in any mixture ratio.

[0054] For example, hydrocarbons such as limonene, α-pinene, β-pinene, terpinene, cedrene, longifolene, and valencene; linalool, citronellol, geraniol, nerol, terpineol, dihydromyrcenol, ethyl linalool, farnesol, nerolidol, cis-3-hexenol, cedarol, menthol, borneol, β-phenylethanol, benzyl alcohol, phenylhexanol, 2,2,6-trimethylcyclohexyl-3-hexanol, 1-(2-tert-butylcyclohexyloxy)-2-butanol, 4-isopropylcyclohexanemethanol, 4-tert-butylcyclohexanol, 4-methyl-2-(2-methylpropyl)tetrahydro-2H-pyran-4-ol, 2-methyl-4-(2,2,3-trimethyl-3 Alcohols such as 2-ethyl-4-(2,2,3-trimethyl-3-cyclopenten-1-yl)-2-buten-1-ol, 2-ethyl-4-(2,2,3-trimethyl-3-cyclopenten-1-yl)-2-buten-1-ol, isobornylcyclohexanol, 3,7-dimethyl-7-methoxyoctan-2-ol; phenols such as eugenol, thymol, and vanillin; linalyl formate, citronellyl formate, geranyl formate, n-hexyl acetate, cis-3-hexenyl acetate, linalyl acetate, citronellyl acetate, geranyl acetate, neryl acetate, terpinyl acetate, nopol acetate, bornyl acetate, isobornyl acetate, o-tert-butylcyclohexyl acetate, p-tert-butylcyclohexyl acetate, tricyclodecenyl acetate, benzyl acetate Ester, styrene acetate, cinnamaldehyde acetate, dimethylbenzyl acetate, 3-pentyltetrahydropyran-4-yl acetate, citronellyl propionate, tricyclodecenyl propionate, allyl cyclohexyl propionate, ethyl 2-cyclohexyl propionate, benzyl propionate, citronellyl butyrate, dimethylbenzyl butyrate, tricyclodecenyl isobutyrate, methyl 2-nonanoate, methyl benzoate, benzyl benzoate, methyl cinnamate, methyl salicylate, n-hexyl salicylate, cis-3-hexenyl salicylate, geranyl tiglate, cis-3-hexenyl tiglate, methyl jasmonate, methyl dihydrojasmonate, methyl 2,4-dihydroxy-3,6-dimethylbenzoate, methylphenyl substituted Esters such as ethyl hydroglycerate, methyl anthranilate, and FRUITATE (ethyl tricyclodecanecarboxylate); aldehydes such as n-octanal, n-decanal, n-dodecanal, 2-methylundecanal, 10-undecanal, citronellal, citral, hydroxycitronellal, dimethyltetrahydrobenzaldehyde, 4(3)-(4-hydroxy-4-methylpentyl)-3-cyclohexene-1-carboxaldehyde, 2-cyclohexylpropionaldehyde, p-tert-butyl-α-methylhydrocinnamaldehyde, p-isopropyl-α-methylhydrocinnamaldehyde, p-ethyl-α,α-dimethylhydrocinnamaldehyde, α-pentylcinnamaldehyde, α-hexylcinnamaldehyde, piperonal, and α-methyl-3,4-methylenedioxyhydrocinnamaldehyde;Methyl heptenone, 4-methylene-3,5,6,6-tetramethyl-2-heptenone, pentylcyclopentanone, 3-methyl-2-(cis-2-penten-1-yl)-2-cyclopenten-1-one, methylcyclopentenolone, rose ketone, γ-methylionone, α-ionone, carvone, menthone, camphor, nootkatone, benzylacetone, anisylacetone, methyl β-naphthone, 2,5-dimethyl -4-hydroxy-3(2H)-furanone, maltol, 7-acetyl-1,2,3,4,5,6,7,8-octahydro-1,1,6,7-tetramethylnaphthalene, musk ketone, civet ketone, cyclopentadecanone, cyclohexadecenone and other ketones; acetaldehyde ethyl phenyl propyl acetal, citral diethyl acetal, phenylacetaldehyde glycerol acetal, ethyl acetoacetate glycol ketal and other acetals and ketals; anethole, β- Ethers such as naphthyl methyl ether, β-naphthyl ethyl ether, limonene oxide, rose oxide, 1,8-cineole, racemic or optically active dodecahydro-3a,6,6,9a-tetramethylnaphtho[2,1-b]furan; nitriles such as citronellyl nitrile; lactones such as γ-nonalactone, γ-undecalactone, σ-decanoalactone, γ-jasmine lactone, coumarin, cyclopentadecalactone, cyclohexacalactone, musk lactone, ethyl brassate, 11-hexadecanoate; natural essential oils and extracts of orange, lemon, bergamot, tangerine, mint, spearmint, lavender, chamomile, rosemary, eucalyptus, sage, basil, rose, geranium, jasmine, ylang ylang, star anise, cloves, ginger, nutmeg, cardamom, cedar, cypress, sandalwood, vetiver, patchouli, and labdanum; and other flavoring substances such as synthetic fragrances.

[0055] In addition, the fragrance composition may also contain surfactants such as polyoxyethylene lauryl sulfate ether; solvents such as dipropylene glycol, diethyl phthalate, ethylene glycol, propylene glycol, methyl myristate, triethyl citrate; antioxidants; colorants, etc. as components other than the blended fragrance materials.

[0056] The isobutyric acid ester of the present invention represented by formula (1) has a floral, green, or fruity aroma, and can be combined with conventional fragrances to impart natural floral, green, or fruity notes. Therefore, it is useful for imparting fragrance to various cosmetics, pharmaceuticals such as health and hygiene products, daily sundry goods, and foods. Furthermore, the isobutyric acid ester of the present invention represented by any of formulas (1-1), (1-2), and (1-4) has a damask-like fruity, floral, or woody aroma, and is therefore useful for imparting fragrance by combining it with conventional fragrances.

[0057] Examples of substances to which the fragrance composition containing the isobutyrate of the present invention represented by formula (1) can be added for the purpose of imparting fragrance or improving the fragrance of a compounding object include cosmetics, health and hygiene materials, sundry goods, beverages, foods, quasi-drugs, and pharmaceuticals. For example, fragrance products such as perfumes and colognes; shampoos, hair dyes, hair tonics, hair creams, mousses, gels, hair waxes, sprays, and other hair cosmetics; toners, essences, creams, emulsions, and facial masks. , foundation, loose powder, lipstick, various cosmetics and other skin cosmetics; dishwashing detergents, laundry detergents, softeners, disinfecting detergents, deodorizing detergents, room fragrances, furniture care, glass cleaners, furniture cleaners, floor cleaners, disinfectants, insecticides, bleaching agents, fungicides, insect repellents, and various other health and hygiene detergents; quasi-drugs such as toothpaste, mouthwash, bath salts, antiperspirants, and perm solutions; sundries such as toilet paper and paper towels; pharmaceuticals; and aroma ingredients in food.

[0058] The amount of the fragrance composition incorporated into the above-mentioned product is not particularly limited and can be selected within a wide range depending on the type, properties, and sensory effect of the product to be scented. For example, it can be 0.00001% by mass or greater, preferably 0.0001% by mass or greater, and more preferably 0.001% by mass or greater. For scented products such as perfume, the amount can be 100% by mass, preferably 80% by mass or less, more preferably 60% by mass or less, and even more preferably 40% by mass or less.

[0059] [Method for producing isobutyrate of the present invention]

[0060] The method for producing the isobutyric acid ester represented by formula (1) of the present invention is not particularly limited, and a method appropriately selected from conventionally known methods can be used.

[0061] For example, a method of acylating the hydroxyl group at the α-position by reacting α-hydroxyisobutyrate with an acylating agent in the presence or absence of a catalyst can be mentioned. Examples of the acylating agent include carboxylic acids such as butyric acid, carboxylic acid anhydrides such as butyric anhydride, carboxylic acid halides such as butyryl chloride and butyryl bromide, and ketene compounds such as ketene. Furthermore, two or more acylating agents selected from these can be used in combination at any ratio.

[0062] The reaction formula when using carboxylic acid, carboxylic anhydride, or carboxylic acid halide is shown in the following formula (2).

[0063]

[0064] In formula (2), R represents a linear, branched, or cyclic alkyl group having 1 to 4 carbon atoms. Y varies depending on the type of acylating agent and represents, for example, a hydroxyl group, an n-butyryloxy group, chlorine, bromine, or iodine.

[0065] The reaction formula when using an enone compound is shown in the following formula (3).

[0066]

[0067] In formula (3), R represents a linear, branched or cyclic alkyl group having 1 to 4 carbon atoms.

[0068] Alternatively, the target α-n-butyryloxyisobutyrate can be produced by subjecting another type of α-n-butyryloxyisobutyrate to an ester exchange reaction with an alcohol in the presence of a catalyst. The reaction formula for this reaction is shown in the following formula (4).

[0069]

[0070] In formula (4), R represents a linear, branched, or cyclic alkyl group having 1 to 4 carbon atoms. R' is not particularly limited as long as it is an alkyl group different from R.

[0071] Similarly, the target α-n-butyryloxyisobutyrate can be produced by subjecting α-n-butyryloxyisobutyric acid to an esterification reaction with an alcohol in the presence of a catalyst. The reaction formula for this reaction is shown in the following formula (5).

[0072]

[0073] In formula (5), R represents a linear, branched or cyclic alkyl group having 1 to 4 carbon atoms.

[0074] The catalyst, reaction mode, reaction conditions and reaction apparatus used in these reactions can use catalysts, reaction methods, reaction conditions and reaction apparatus known in the past, without particular restrictions. In addition, the method for refining the compound of the formula (1) obtained can also adopt known purification methods in the past, without any restrictions.

[0075] Example

[0076] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples.

[0077] The reaction performance was evaluated according to the following formula.

[0078] Reaction yield (%) = [(the number of moles of the produced ester in the reaction solution) / (the number of moles of the raw material ester in the feed solution)] × 100%

[0079] Gas chromatography analysis (GC analysis)

[0080] Device: GC-2010 (manufactured by Shimadzu Corporation)

[0081] Detector: FID

[0082] Chromatographic column: DB-1 (J&W capillary column, product name) (0.25 mm φ × 60 m × 0.25 μm)

[0083] NMR spectrum analysis

[0084] Esters were identified by 1 H-NMR determination and 13 C-NMR measurement was performed under the following conditions.

[0085] Device: ECA500 (manufactured by JEOL Ltd.)

[0086] 〔 1 H-NMR

[0087] Nuclide: 1 H

[0088] Measurement frequency: 500MHz

[0089] Measurement sample: 5% CDCl3 solution

[0090] 〔 13 C-NMR

[0091] Nuclide: 13 C

[0092] Measurement frequency: 125MHz

[0093] Test sample: 5% CDCl3 solution

[0094] Gas chromatography-mass spectrometry (GC-MS analysis)

[0095] Compound identification can also be performed by determining the molecular weight using GC-MS (chemical ionization [CI+], high-resolution mass spectrometry [millimas]). The measurement conditions are as follows.

[0096] GC apparatus: Agilent 7890A (manufactured by Agilent Technologies, trade name)

[0097] GC measurement conditions

[0098] Chromatographic column: DB-1 (J&W capillary column, product name) (0.25 mm φ × 30 m × 0.25 μm)

[0099] MS device: JMS-T100GCV (manufactured by JEOL Ltd.)

[0100] MS determination conditions: chemical ionization

[0101] Detector conditions: 200 eV, 300 μA

[0102] Reagent gas: isobutane

[0103] The precise molecular weight values ​​of the fragments detected in the protonated state by chemical ionization and the chemical composition formulas assigned thereto were recorded.

[0104] <Product separation by chromatography>

[0105] The products were isolated by chromatography using the following materials.

[0106] Filler: Wako Gel C-200 (trade name, manufactured by Wako Pure Chemical Industries, Ltd.)

[0107] Developing solvent: ethyl acetate-hexane

[0108] <Example 1: Synthesis of methyl α-n-butyryloxyisobutyrate>

[0109] A 200 ml glass round-bottom flask equipped with a cooling tube and a stirrer was charged with 20.0 g of methyl α-hydroxyisobutyrate (manufactured by Mitsubishi Gas Chemical Co., Ltd.), 29.4 g of butyric anhydride (manufactured by Wako Pure Chemical Industries, Ltd.), 13.6 g of pyridine (manufactured by Wako Pure Chemical Industries, Ltd.), and 2.1 g of 4-dimethylaminopyridine (manufactured by Wako Pure Chemical Industries, Ltd.). The mixture was stirred at room temperature to 40°C for 24 hours to allow for reaction. GC analysis of the reaction solution confirmed that methyl α-hydroxyisobutyrate was completely consumed by the reaction with butyric anhydride. Methyl α-n-butyryloxyisobutyrate was obtained in a reaction yield of 93% through the reaction of the following formula (7). The mixture was then washed three times with a 10% aqueous sodium bicarbonate solution and twice with a saturated aqueous sodium chloride solution, and dried over magnesium sulfate. Column chromatography was then performed to obtain 21.2 g of methyl α-n-butyryloxyisobutyrate (GC analysis purity (hereinafter also referred to as GC purity): >99.9%). The results of NMR spectrum analysis and GC-MS analysis of the product are shown below.

[0110] 〔Methyl α-n-butyryloxyisobutyrate〕

[0111] 1 H NMR(500MHz, CDCl3)δ0.96(3H,t,J=7.5Hz),1.55(6H,s),1.65(2H,sext,J=7.5Hz),2.29(2H,t,J=7.5Hz),3.72(3H,s)

[0112] 13C NMR (125MHz, CDCl3) δ13.46,18.34,24.59,36.14,52.27,77.83,172.65,173.19

[0113] Exact molecular weight 189.11383 (C9H 16 O4, mother peak), 157.08676 (C8H 12 O3)

[0114]

[0115] <Reference Example 1: Synthesis of Ethyl α-Hydroxyisobutyrate>

[0116] A 300ml glass flask equipped with a distillation tube was charged with 56.7g of methyl α-hydroxyisobutyrate (Mitsubishi Gas Chemical Co., Ltd.), 33.2g of ethanol (Wako Pure Chemical Industries, Ltd.), and 0.92g of tetraethoxytitanium (Wako Pure Chemical Industries, Ltd.). The transesterification reaction was carried out under reflux at atmospheric pressure, with the generated methanol removed from the system, for 96 hours. As a result, ethyl α-hydroxyisobutyrate was obtained with a reaction yield of 97%. Water was added to the reaction system to deactivate the catalyst, followed by vacuum distillation. 46.9g of ethyl α-hydroxyisobutyrate (GC purity: 99.6%) was obtained as a fraction at 71 mmHg and 77°C.

[0117] <Reference Examples 2 to 5: Synthesis of Various α-Hydroxyisobutyrates>

[0118] Using the same reaction apparatus as in Reference Example 1, appropriate amounts of methyl α-hydroxyisobutyrate (manufactured by Mitsubishi Gas Chemical Co., Ltd.) were subjected to a transesterification reaction with various alcohols (n-propanol, isopropanol, n-butanol, and isobutanol) in the presence of a suitable catalyst such as tetraalkoxytitanium and / or sodium alkoxide, and in the presence of a solvent such as hexane or toluene, as appropriate. The resulting methanol was removed from the reaction system by distillation or azeotropic distillation with the reaction solvent under the reaction conditions, completing the transesterification reaction. Separation procedures were then performed as in Reference Example 1 to yield the following α-hydroxyisobutyrates. The GC purity of the resulting isobutyrates is also reported.

[0119] α-Hydroxyisobutyric acid n-propyl ester (GC purity: 99.8%)

[0120] Isopropyl α-hydroxyisobutyrate (GC purity: 99.6%)

[0121] α-Hydroxyisobutyric acid n-butyl ester (GC purity: 99.9%)

[0122] Isobutyl α-hydroxyisobutyrate (GC purity: 99.6%)

[0123] <Example 2: Synthesis of ethyl α-n-butyryloxyisobutyrate>

[0124] Using the same reaction apparatus as in Example 1, the reaction was conducted using appropriate amounts of ethyl α-hydroxyisobutyrate prepared in Reference Example 1, butyric anhydride (Wako Pure Chemical Industries, Ltd.), pyridine (Wako Pure Chemical Industries, Ltd.), and 4-dimethylaminopyridine (Wako Pure Chemical Industries, Ltd.). Following the same procedures as in Example 1, ethyl α-n-butyryloxyisobutyrate (GC purity: 99.83%) was obtained. The results of NMR and GC-MS analyses of the product are shown below.

[0125] 〔α-n-Butyryloxyethyl isobutyrate〕

[0126] 1 H NMR(500MHz, CDCl3)δ0.96(3H,t,J=7.5Hz),1.25(3H,t,J=7.0Hz),1.54(6H,s),1.65(2H,sext,J=7.5Hz),2.29(2H,t,J=7.5Hz),4.18(2H,q,J=7.0Hz)

[0127] 13 C NMR (125MHz, CDCl3) δ13.51,13.99,18.37,24.56,36.17,61.15,77.90,172.56,172.67

[0128] The exact molecular weight is 203.13157 (C 10 H 18 O4, mother peak), 157.08746 (C8H 12 O3)

[0129] <Examples 3 to 6: Synthesis of α-n-butyryloxyisobutyrate>

[0130] Using the same reaction apparatus as in Example 2, reactions were carried out using appropriate amounts of the α-hydroxyisobutyrates prepared in Reference Examples 2 to 5, butyric anhydride (Wako Pure Chemical Industries, Ltd.), pyridine (Wako Pure Chemical Industries, Ltd.), and 4-dimethylaminopyridine (Wako Pure Chemical Industries, Ltd.). Following the same procedures as in Example 1, the following α-n-butyryloxyisobutyrates were obtained by column chromatography. The GC purity, NMR spectroscopic analysis, and GC-MS analysis results of the obtained esters are also reported.

[0131] [Example 3: α-n-butyryloxyisobutyric acid n-propyl ester]

[0132] GC purity: 99.81%

[0133] 1 H NMR(500MHz, CDCl3)δ0.94(3H,t,J=7.5Hz),0.96(3H,t,J=7.5Hz),1.55(6H,s),1.61-1.69(4H,m),2.29(2H,t,J=7.5Hz),4.08(2H,t,J=6.5Hz)

[0134] 13 C NMR (125MHz, CDCl3) δ10.29,13.53,18.34,21.82,24.62,36.18,66.76,77.96,172.56,172.75

[0135] The exact molecular weight is 217.14467 (C 11 H 20 O4, mother peak), 157.08749 (C8H 12 O3)

[0136] [Example 4: α-n-Butyryloxyisobutyric acid isopropyl ester]

[0137] GC purity: 99.96%

[0138] 1 H NMR(500MHz, CDCl3)δ0.97(3H,t,J=7.5Hz),1.22(6H,d,J=6.5Hz),1.53(6H,s),1.65(2H,sext,J=7.5Hz),2.28(2H,t,J=7.5Hz),5.03(1H,sep,J=6.5Hz)

[0139] 13 C NMR (125MHz, CDCl3) δ13.59,18.42,21.55,24.53,36.22,68.57,77.98,172.15,172.48

[0140] The exact molecular weight is 217.14709 (C 11 H 20 O4, mother peak), 175.09776 (C8H 14 O4)

[0141] [Example 5: n-Butyl α-n-butyryloxyisobutyrate]

[0142] GC purity: 99.91%

[0143] 1H NMR(500MHz, CDCl3)δ0.93(3H,t,J=7.5Hz),0.96(3H,t,J=7.5Hz),1.37(2H,sext,J= 7.5Hz),1.54(6H,s),1.58-1.69(4H,m),2.28(2H,t,J=7.5Hz),4.12(2H,t,J=6.5Hz)

[0144] 13 C NMR (125MHz, CDCl3) δ13.54,13.65,18.35,19.04,24.61,30.45,36.19,65.05,77.96,172.56,172.77

[0145] The exact molecular weight is 231.16103 (C 12 H 22 O4, mother peak), 157.08815 (C8H 12 O3)

[0146] [Example 6: α-n-Butyryloxyisobutyric acid isobutyl ester]

[0147] GC purity: 99.62%

[0148] 1 H NMR(500MHz, CDCl3)δ0.93(6H,d,J=6.5Hz),0.96(3H,t,J=7.5Hz),1.56(6H,s),1 .65(2H,sext,J=7.5Hz),1.94(1H,m),2.29(2H,t,J=7.5Hz),3.90(2H,d,J=6.5Hz)

[0149] 13 C NMR (125MHz, CDCl3) δ13.57,18.33,19.00,24.66,27.65,36.20,71.24,78.01,172.56,172.72

[0150] The exact molecular weight is 231.16303 (C 12 H 22 O4, mother peak), 157.08976 (C8H 12 O3)

[0151] The aroma of various α-n-butyryloxyisobutyrates obtained by the above-mentioned method was evaluated by a perfumer. The results are shown in Table 1.

[0152] [Table 1]

[0153] Table 1

[0154]

[0155] <Evaluation of Biodegradability of Fragrance Materials>

[0156] One of the methods for evaluating the biodegradability of a compound is OECD Test Guideline 301C, which can be used to determine the biodegradability of a compound based on the biochemical oxygen demand and actual oxygen consumption rate in an aqueous solution containing the compound and aerobic microorganisms.

[0157] As a method for easily and accurately estimating the biodegradation probability of a compound according to this test method from the chemical structure of a test substance, calculation software called "Biowin5" and "Biowin6" are known.

[0158] This software is released to the public as a module of "The Estimations Programs Interface for Windows version 4.1," a computational software package developed by the United States Environmental Protection Agency (EPA) for evaluating the environmental impacts of chemical substances. It is used for compound classification under the Globally Harmonized System (GHS) and for the EPA's review of new chemical substances. The software was used to evaluate the biodegradability of existing fragrance materials and the compounds of the present invention.

[0159] As representative examples of existing fragrance materials similar to the compounds of the present invention, (E)-α-damascenone and (E)-β-damascenone, which have floral notes, were selected and evaluated alongside the compounds of the present invention. Tables 2 and 3 show the SMILES formula used for software input and the output results of the probability of good degradability based on "Biowin5 (linear prediction model)" and "Biowin6 (non-morphological prediction model)." Larger numerical values ​​indicate better degradability. Values ​​of 0.5 or higher indicate good degradability (denoted by "A" in the tables), while values ​​of less than 0.5 indicate poor degradability (denoted by "B" in the tables).

[0160] As shown in Tables 2 and 3, the compounds of the present invention exhibit promising results for better biodegradability compared to similar existing fragrance materials (E)-α-damascenone and (E)-β-damascenone. The compounds of the present invention readily biodegrade after release into the environment as fragrances, demonstrating a trend toward less environmental impact.

[0161] [Table 2]

[0162] Table 2

[0163]

[0164] [Table 3]

[0165] Table 3

[0166]

[0167] <Example 7: Lily Bouquet Type Fragrance Composition>

[0168] 5.0 parts by mass of isopropyl α-n-butyryloxyisobutyrate obtained in Example 4 was added to 95.0 parts by mass of a fragrance composition having the composition shown in Table 4 to prepare a fragrance composition.

[0169] Perfumers conducted aroma evaluations and found that adding isopropyl α-n-butyryloxyisobutyrate from Example 4 to the fragrance composition having the composition described in Table 4 resulted in a fusion of rose-like floral and fruity notes, resulting in a rich, sweet, and broad floral aroma. The result was a fragrance composition with a lily-of-the-valley aroma that imparted a natural, sweet, fruity, and rose-like floral aroma.

[0170] The fragrance of the perfume composition is suitable for imparting fragrance to shampoo, toner, skin cream, lotion, softener, soap and the like.

[0171] [Table 4]

[0172] Compounding ingredients parts by mass Hydroxycitronellal 10.0 JASMIN BASE A-15363 / FC(Yamamoto Perfumery) 7.0 ISO E SUPER(IFF) 8.0 IFF 0.8 Benzyl acetate 1.0 Benzyl propionate 0.6 Citronella oil 0.1 Citronellol 8.0 Cyclamen aldehyde 0.7 Musk Galax 50BB (IFF) 4.5 Geraniol 6.5 Hexyl cinnamaldehyde 1.5 Indole (Symrise) 0.5 Lilial 20.0 Linalool 2.5 HEDION (Firmenich) 10.0 Nerolidol 3.0 Phenylacetaldehyde dimethyl acetal 0.3 Phenylethyl alcohol 10.0 total 95.0

[0173] Industrial applicability

[0174] The isobutyrate compound having an n-butyryloxy group at the α-position of the present invention has an excellent aroma and is expected to be used as a fragrance itself. In addition, by using the compound as a fragrance blending material, a fragrance composition having excellent aroma can be obtained, and the desired aroma-imparting properties can be exerted by incorporating the compound into various products.

[0175] Furthermore, it was shown that the compounds obtained in the examples all had excellent biodegradability, had low environmental impact, and were suitable for use.

Claims

1. A compound represented by formula (1), In formula (1), R is selected from methyl, ethyl, n-propyl, isopropyl, n-butyl and isobutyl.

2. The compound according to claim 1, wherein In formula (1), R is a methyl group.

3. The compound according to claim 1, wherein In formula (1), R is an ethyl group.

4. The compound according to claim 1, wherein In formula (1), R is n-propyl.

5. The compound according to claim 1, wherein In formula (1), R is an isopropyl group.

6. The compound according to claim 1, wherein In formula (1), R is n-butyl.

7. The compound according to claim 1, wherein In formula (1), R is an isobutyl group.

8. A flavor composition comprising the compound according to any one of claims 1 to 7 as an active ingredient.

9. Use of the compound according to any one of claims 1 to 7 as a fragrance.

10. The use according to claim 9, wherein The compound according to any one of claims 2, 3 and 5 imparts a damask-like floral or fruity fragrance.

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