Dicarbonyl compound with flower and fruit fragrance, preparation method of dicarbonyl compound and flower and fruit fragrance base

Abstract

The invention relates to the technical field of flavors and fragrances, in particular to a dicarbonyl compound with flower and fruit fragrance, a preparation method of the dicarbonyl compound and a flower and fruit fragrance base. The dicarbonyl compound with the flower and fruit fragrance has the following structural formula: the dicarbonyl compound with the flower and fruit fragrance prepared by the invention is 2-acetyl-3-(5-allyl-2-methoxyphenyl)-2-cyclopentene-1-carboxylic acid methyl ester, and the compound has special spiral quaternary carbon, has special tropical flower and fruit fragrance fragrance, and can be used for preparing the compound with the flower and fruit fragrance. With syringa oblata fragrance, the fragrance is elegant, and the fragrance holding time is long. The preparation method of the compound is simple in process, convenient to operate and control, high in production efficiency and suitable for industrial production. The dicarbonyl compound with the flower and fruit fragrance is added into the prepared flower and fruit fragrance base, and compared with the flower and fruit fragrance base without the compound, the flower and fruit fragrance base has more prominent special tropical flower and fruit fragrance, more prominent special fragrance and slightly elegant syringa oblata fragrance, and the fragrance quality of the base is remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of flavors and fragrances, and in particular to a dicarbonyl compound with floral and fruity aroma, a preparation method thereof, and a floral and fruity aroma base. Background Art

[0002] In the prior art, spices and flavors are often used as fixatives, coordinators, or flavoring agents to enhance the aroma and sensory experience of products, improve product quality, and meet the needs of different consumers. Therefore, it is of great significance to develop new flavor and fragrance compounds with unique aroma and sensory experience, enrich the variety of flavors and fragrances, further enrich the aroma and sensory experience of products, and promote the development of the flavor and fragrance industry and other related technologies. In view of this, the present invention has developed a dicarbonyl compound with a floral and fruity aroma, and the developed compound has a special tropical floral and fruity aroma with a lilac fragrance. The chemical has an elegant aroma and a long lasting fragrance. It has important uses in the field of daily chemical perfumery. However, domestic and international flavor and fragrance companies have not yet launched this compound. Therefore, this compound has important uses and broad market prospects in the field of perfumery. Summary of the Invention

[0003] In order to overcome the shortcomings and deficiencies in the prior art, the object of the present invention is to provide a dicarbonyl compound with a floral and fruity aroma, which has a distinctive spiroquaternary carbon. The compound has a special tropical floral and fruity aroma and a lilac fragrance. The aroma is elegant and the fragrance lasts for a long time. It has important application value and market prospects in the field of perfumery.

[0004] Another object of the present invention is to provide a method for preparing a dicarbonyl compound with floral and fruity aroma, which has a simple process, is easy to operate and control, has high production efficiency, and is suitable for industrial production.

[0005] Another object of the present invention is to provide a fruity aroma base, which is added with the above-mentioned dicarbonyl compound with floral and fruity aroma. Compared with the floral and fruity aroma base without the compound, the fruity aroma base has a more prominent special tropical floral and fruity aroma, a more distinctive aromatic aroma, a slightly elegant lilac fragrance, and a significantly improved aroma quality of the aroma base.

[0006] The purpose of the present invention is achieved through the following technical solution: A dicarbonyl compound with floral and fruity aroma has the following structural formula:

[0007]

[0008] The dicarbonyl compound with floral and fruity aroma can be named: 2-acetyl-3-(5-allyl-2-methoxyphenyl)-2-cyclopentene-1-carboxylic acid methyl ester.

[0009] The dicarbonyl compound with floral and fruity aroma of the present invention is prepared through a key palladium-catalyzed tandem cyclization reaction. It has a distinctive spiroquaternary carbon, a special tropical floral and fruity aroma, and is accompanied by a lilac fragrance, and has important uses in the field of daily chemical perfumery.

[0010] Another object of the present invention is achieved by the following technical solution: a method for preparing a dicarbonyl compound with floral and fruity aroma, comprising the following steps:

[0011] Step 1: Using methyl acetoacetate and iodide as raw materials, prepare methyl 2-acetylhex-5-ynoate. The structural formula of the iodide is shown below:

[0012]

[0013] The structural formula of methyl 2-acetylhex-5-ynoate is shown below:

[0014]

[0015] Step 2: Using allyl anisole as a raw material, prepare 2-bromo-4-allyl anisole. The structural formula of allyl anisole is shown below:

[0016]

[0017] The structural formula of 2-bromo-4-allylanisole is shown below:

[0018]

[0019] Step 3: Using the 2-acetylhex-5-ynoic acid methyl ester prepared in step 1 and the 2-bromo-4-allylanisole prepared in step 2 as raw materials, and after separation and purification, obtaining a dicarbonyl compound with a floral and fruity aroma, wherein the dicarbonyl compound with a floral and fruity aroma is 2-acetyl-3-(5-allyl-2-methoxyphenyl)-2-cyclopentene-1-carboxylic acid methyl ester.

[0020] Furthermore, in the step 1, the preparation method of methyl 2-acetylhex-5-ynoate comprises the following steps:

[0021] A1. Place kerosene-coated sodium hydride in a reaction vessel, add anhydrous THF to dissolve, cool to -1-1°C, slowly add methyl acetoacetate, and stir in an ice bath for 0.2-0.8 hours until no obvious bubbles are generated. Then add the iodide to the reaction system, and heat to 55-65°C for 70-74 hours.

[0022] A2. Saturated aqueous ammonium chloride was added to quench the reaction, the organic phase was separated, and the residual organic phase was extracted from the aqueous phase with ethyl acetate; the combined organic phase was dried and concentrated, and then separated by column chromatography to obtain a light yellow oily liquid, namely, 2-acetylhex-5-ynoic acid methyl ester.

[0023] Furthermore, in step A1, 180-220 mmol of sodium hydride wrapped in kerosene is placed in a reaction vessel, 580-620 mL of anhydrous THF is added for dissolution, and the mixture is cooled to -1-1°C. Then, 180-220 mmol of methyl acetoacetate is slowly added, and the mixture is stirred in an ice bath for 0.2-0.8 hours until no obvious bubbles are generated. Then, 200-208 mmol of iodide is added, and the temperature is raised to 55-65°C for 70-74 hours.

[0024] Furthermore, in step 2, the preparation method of 2-bromo-4-allylanisole comprises the following steps:

[0025] B1, allyl anisole, acetic acid and part of the pyridinium tribromide salt were added to the reactor in sequence, and the reaction was carried out at room temperature for 25-35 minutes, and then the remaining pyridinium tribromide salt was added and the reaction was continued for 22-24 hours. After the reaction was completed, most of the acetic acid was removed by rotary evaporation to obtain a red liquid;

[0026] B2. Dilute the red liquid with toluene, wash with a saturated aqueous solution of sodium bicarbonate and then with an aqueous solution of sodium thiosulfate, separate the liquids, and then dry the organic phase with anhydrous sodium sulfate and concentrate to obtain a brown oily liquid;

[0027] B3. The oily liquid obtained in step B1 was dissolved in ether, zinc powder and acetic acid were added, and the mixture was refluxed for 3-5 hours, cooled to room temperature, and reacted for 22-24 hours. After the reaction, the reactant was filtered, and the filtrate was washed with saturated sodium bicarbonate solution, dried over anhydrous sodium sulfate, and concentrated to obtain a crude product. The crude product was separated by silica gel column chromatography to obtain a colorless oily liquid, thereby preparing 2-bromo-4-allylanisole.

[0028] Furthermore, in step B1, 80-120 mmol of allylanisole, 280-320 mL of acetic acid and part of 130-134 mmol of pyridinium tribromide are added to the reactor in sequence, and the mixture is reacted at room temperature for 25-35 minutes. Then, the remaining 130-134 mmol of pyridinium tribromide is added and the reaction is continued for 22-24 hours. After the reaction is completed, most of the acetic acid is removed by rotary evaporation to obtain a red liquid.

[0029] Furthermore, in step B3, the oily liquid obtained in step B1 is dissolved in 180-220 mL of ether, 5-6 g of zinc powder and 3-8 mL of acetic acid are added, and the mixture is refluxed for 3-5 hours and then cooled to room temperature and reacted for 22-24 hours. After the reaction is completed, the reactant is filtered, and the filtrate is washed with a saturated sodium bicarbonate solution, dried over anhydrous sodium sulfate, and concentrated to obtain a crude product. The crude product is separated by silica gel column chromatography to obtain a colorless oily liquid, thereby preparing 2-bromo-4-allylanisole.

[0030] Furthermore, in step 3, the preparation method of methyl 2-acetyl-3-(5-allyl-2-methoxyphenyl)-2-cyclopentene-1-carboxylate comprises the following steps:

[0031] C1. Palladium catalyst XPhos Pd G3, lithium hydroxide, dried 4A molecular sieves, and DCE were sequentially added to a reactor, and argon protection was replaced. Then, the reaction substrates 2-acetylhex-5-ynoic acid methyl ester and 2-bromo-4-allylanisole were quickly added to the reactor, and the temperature was raised to 45-55° C. and the reaction was carried out for 23-25 ​​hours.

[0032] C2. After the reaction, the reactant obtained in step C1 was diluted with DCM, and then solid ammonium chloride was added and stirred for 8-12 minutes, and then solid anhydrous sodium sulfate was added and stirred for 8-12 minutes, and then filtered through diatomaceous earth; the obtained filtrate was directly concentrated under reduced pressure and separated by silica gel column chromatography to obtain a colorless liquid, that is, 2-acetyl-3-(5-allyl-2-methoxyphenyl)-2-cyclopentene-1-carboxylic acid methyl ester was prepared.

[0033] Another object of the present invention is achieved through the following technical solution: a floral and fruity fragrance base, comprising the following raw materials in parts by weight: 45-55 parts of methyl 2-acetyl-3-(5-allyl-2-methoxyphenyl)-2-cyclopentene-1-carboxylate, 8-12 parts of cyclopentyl ester, 12-18 parts of ethyl methyl naphthalene ketone, 28-32 parts of geraniol, 42-48 parts of farnesol, 3-8 parts of geranyl acetate, 12-16 parts of anisaldehyde, 18-22 parts of isovalerate, 12-16 parts of lemon oil terpenes, 76-84 parts of γ-caprolactone, 22-28 parts of linalyl acetate, 18-22 parts of isomethyl ionone, 6-10 parts of allyl hexanoate, 18-22 parts of ethyl heptanoate, 6-10 parts of neral, 8-12 parts of damascenone, and 600-700 parts of propylene glycol.

[0034] The beneficial effects of the present invention are as follows: the dicarbonyl compound with floral and fruity aroma prepared by the present invention is 2-acetyl-3-(5-allyl-2-methoxyphenyl)-2-cyclopentene-1-carboxylic acid methyl ester, and the compound is prepared by a key palladium-catalyzed tandem cyclization reaction. It has a distinctive spiroquaternary carbon, a special tropical floral and fruity aroma, and is accompanied by a lilac fragrance. The fragrance is elegant and has a long lasting fragrance time, and has important application value and market prospects in the field of perfumery. The preparation method of the compound is simple in process, easy to operate and control, has high production efficiency, and is suitable for industrial production. The fruity aroma base prepared by the present invention is added with the above-mentioned dicarbonyl compound with floral and fruity aroma. Compared with the floral and fruity aroma base without the addition of the compound, it has a more prominent special tropical floral and fruity aroma, a more prominent distinctive aromatic aroma, a slightly elegant lilac fragrance, and a significantly improved aroma quality of the aroma base. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is the hydrogen spectrum (400 MHz, CDCl3) of methyl 2-acetyl-3-(5-allyl-2-methoxyphenyl)-2-cyclopentene-1-carboxylate prepared in Example 1.

[0036] Figure 2 This is the carbon spectrum (100 MHz, CDCl3) of methyl 2-acetyl-3-(5-allyl-2-methoxyphenyl)-2-cyclopentene-1-carboxylate prepared in Example 1. DETAILED DESCRIPTION

[0037] In order to facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments and drawings. The contents mentioned in the embodiments are not intended to limit the present invention.

[0038] In an embodiment of the present invention, a dicarbonyl compound having a floral and fruity aroma has the following structural formula:

[0039]

[0040] The dicarbonyl compound with floral and fruity aroma can be named: 2-acetyl-3-(5-allyl-2-methoxyphenyl)-2-cyclopentene-1-carboxylic acid methyl ester.

[0041] In an embodiment of the present invention, a method for preparing a dicarbonyl compound having a floral and fruity aroma comprises the following steps:

[0042] Step 1: Using methyl acetoacetate and iodide as raw materials, prepare methyl 2-acetylhex-5-ynoate. The structural formula of the iodide is shown below:

[0043]

[0044] The structural formula of methyl 2-acetylhex-5-ynoate is shown below:

[0045]

[0046] Step 2: Using allyl anisole as a raw material, prepare 2-bromo-4-allyl anisole. The structural formula of allyl anisole is shown below:

[0047]

[0048] The structural formula of 2-bromo-4-allylanisole is shown below:

[0049]

[0050] Step 3: Using the 2-acetylhex-5-ynoic acid methyl ester prepared in step 1 and the 2-bromo-4-allylanisole prepared in step 2 as raw materials, and after separation and purification, obtaining a dicarbonyl compound with a floral and fruity aroma, wherein the dicarbonyl compound with a floral and fruity aroma is 2-acetyl-3-(5-allyl-2-methoxyphenyl)-2-cyclopentene-1-carboxylic acid methyl ester.

[0051] Furthermore, in the step 1, the preparation method of methyl 2-acetylhex-5-ynoate comprises the following steps:

[0052] A1. Place kerosene-coated sodium hydride in a reaction vessel, add anhydrous THF to dissolve, cool to -1-1°C, slowly add methyl acetoacetate, and stir in an ice bath for 0.2-0.8 hours until no obvious bubbles are generated. Then add the iodide to the reaction system, and heat to 55-65°C for 70-74 hours.

[0053] A2. Saturated aqueous ammonium chloride was added to quench the reaction, the organic phase was separated, and the residual organic phase was extracted from the aqueous phase with ethyl acetate; the combined organic phase was dried and concentrated, and then separated by column chromatography to obtain a light yellow oily liquid, namely, 2-acetylhex-5-ynoic acid methyl ester.

[0054] Furthermore, in step A1, 180-220 mmol of sodium hydride wrapped in kerosene is placed in a reaction vessel, 580-620 mL of anhydrous THF is added for dissolution, and the mixture is cooled to -1-1°C. Then, 180-220 mmol of methyl acetoacetate is slowly added, and the mixture is stirred in an ice bath for 0.2-0.8 hours until no obvious bubbles are generated. Then, 200-208 mmol of iodide is added, and the temperature is raised to 55-65°C for 70-74 hours.

[0055] Furthermore, in step 2, the preparation method of 2-bromo-4-allylanisole comprises the following steps:

[0056] B1, allyl anisole, acetic acid and part of the pyridinium tribromide salt were added to the reactor in sequence, and the reaction was carried out at room temperature for 25-35 minutes, and then the remaining pyridinium tribromide salt was added and the reaction was continued for 22-24 hours. After the reaction was completed, most of the acetic acid was removed by rotary evaporation to obtain a red liquid;

[0057] B2. Dilute the red liquid with toluene, wash with a saturated aqueous solution of sodium bicarbonate and then with an aqueous solution of sodium thiosulfate, separate the liquids, and then dry the organic phase with anhydrous sodium sulfate and concentrate to obtain a brown oily liquid;

[0058] B3. The oily liquid obtained in step B1 was dissolved in ether, zinc powder and acetic acid were added, and the mixture was refluxed for 3-5 hours, cooled to room temperature, and reacted for 22-24 hours. After the reaction, the reactant was filtered, and the filtrate was washed with saturated sodium bicarbonate solution, dried over anhydrous sodium sulfate, and concentrated to obtain a crude product. The crude product was separated by silica gel column chromatography to obtain a colorless oily liquid, thereby preparing 2-bromo-4-allylanisole.

[0059] Furthermore, in step B1, 80-120 mmol of allylanisole, 280-320 mL of acetic acid and part of 130-134 mmol of pyridinium tribromide are added to the reactor in sequence, and the mixture is reacted at room temperature for 25-35 minutes. Then, the remaining 130-134 mmol of pyridinium tribromide is added and the reaction is continued for 22-24 hours. After the reaction is completed, most of the acetic acid is removed by rotary evaporation to obtain a red liquid.

[0060] Furthermore, in step B3, the oily liquid obtained in step B1 is dissolved in 180-220 mL of ether, 5-6 g of zinc powder and 3-8 mL of acetic acid are added, and the mixture is refluxed for 3-5 hours and then cooled to room temperature and reacted for 22-24 hours. After the reaction is completed, the reactant is filtered, and the filtrate is washed with a saturated sodium bicarbonate solution, dried over anhydrous sodium sulfate, and concentrated to obtain a crude product. The crude product is separated by silica gel column chromatography to obtain a colorless oily liquid, thereby preparing 2-bromo-4-allylanisole.

[0061] Furthermore, in step 3, the preparation method of methyl 2-acetyl-3-(5-allyl-2-methoxyphenyl)-2-cyclopentene-1-carboxylate comprises the following steps:

[0062] C1. Palladium catalyst XPhos Pd G3, lithium hydroxide, dried 4A molecular sieves, and DCE were sequentially added to a reactor, and argon protection was replaced. Then, the reaction substrates 2-acetylhex-5-ynoic acid methyl ester and 2-bromo-4-allylanisole were quickly added to the reactor, and the temperature was raised to 45-55° C. and the reaction was carried out for 23-25 ​​hours.

[0063] C2. After the reaction, the reactant obtained in step C1 was diluted with DCM, and then solid ammonium chloride was added and stirred for 8-12 minutes, and then solid anhydrous sodium sulfate was added and stirred for 8-12 minutes, and then filtered through diatomaceous earth; the obtained filtrate was directly concentrated under reduced pressure and separated by silica gel column chromatography to obtain a colorless liquid, that is, 2-acetyl-3-(5-allyl-2-methoxyphenyl)-2-cyclopentene-1-carboxylic acid methyl ester was prepared.

[0064] In some embodiments of the present invention, a floral and fruity fragrance base comprises the following raw materials in parts by weight: 45-55 parts of methyl 2-acetyl-3-(5-allyl-2-methoxyphenyl)-2-cyclopentene-1-carboxylate, 8-12 parts of cyclopentyl ester, 12-18 parts of ethyl methyl naphthalene ketone, 28-32 parts of geraniol, 42-48 parts of farnesol, 3-8 parts of geranyl acetate, 12-16 parts of anisaldehyde, 18-22 parts of isovalerate, 12-16 parts of lemon oil terpenes, 76-84 parts of γ-caprolactone, 22-28 parts of linalyl acetate, 18-22 parts of isomethyl ionone, 6-10 parts of allyl hexanoate, 18-22 parts of ethyl heptanoate, 6-10 parts of neral, 8-12 parts of damascenone, and 600-700 parts of propylene glycol.

[0065] In a typical embodiment of the present invention, a floral and fruity fragrance base comprises the following raw materials in parts by weight: 50 parts of methyl 2-acetyl-3-(5-allyl-2-methoxyphenyl)-2-cyclopentene-1-carboxylate, 10 parts of cyclopentyl ester, 15 parts of ethyl methyl naphthalene ketone, 30 parts of geraniol, 45 parts of farnesol, 5 parts of geranyl acetate, 14 parts of anisaldehyde, 20 parts of isovalerate, 14 parts of lemon oil terpenes, 80 parts of γ-caprolactone, 25 parts of linalyl acetate, 20 parts of isomethyl ionone, 8 parts of allyl hexanoate, 20 parts of ethyl heptanoate, 8 parts of neral, 10 parts of damascena, and 626 parts of propylene glycol.

[0066] Example 1

[0067] This embodiment provides a dicarbonyl compound with a floral and fruity aroma, having the following structural formula:

[0068]

[0069] The chemical name of the dicarbonyl compound with floral and fruity aroma is methyl 2-acetyl-3-(5-allyl-2-methoxyphenyl)-2-cyclopentene-1-carboxylate.

[0070] The preparation method of the dicarbonyl compound with floral and fruity aroma comprises the following steps:

[0071] Step 1: Preparation of 2-acetylhex-5-ynoic acid methyl ester. The chemical reaction formula for the preparation of 2-acetylhex-5-ynoic acid methyl ester is as follows:

[0072]

[0073] A1. In a reaction vessel, sodium hydride (sodium hydride content 60%, 8.1 g, 200 mmol) coated with kerosene was placed, a stirrer was added, anhydrous THF (600 mL) was added, and the mixture was cooled to 0°C. Methyl acetoacetate (23.2 g, 200 mmol) was slowly added, and the mixture was reacted in an ice bath for 0.5 hour until no obvious bubbles were generated. Then, iodide (36.7 g, 204 mmol) was added, and the temperature was raised to 60°C and the reaction was carried out for 72 hours. The structural formula of methyl acetoacetate is shown in Formula 1; the structural formula of iodide is shown in Formula 2.

[0074] A2. After the reaction was completed, the mixture was cooled to room temperature, saturated aqueous ammonium chloride solution (300 mL) was added to quench the reaction, and the aqueous phase was extracted with ethyl acetate (200 mL × 3); the combined organic phase was dried and concentrated, and separated by column chromatography (silica gel, Hex / EA = 10:1) to obtain 16.1 g of a light yellow oily liquid, namely 2-acetylhex-5-ynoic acid methyl ester, with a yield of 48%; 2-acetylhex-5-ynoic acid methyl ester is shown in Formula 3, which has the following NMR spectral characteristics:

[0075] 1 H NMR (400MHz, CDCl3) δ3.74-3.70(m,1H),3.71(s,3H),2.26(s,3H),2.25-2.22(m,2H),2.06-2.02(m,2H),1.99(t,J=2.6Hz,1H);

[0076] 13 C NMR (100MHz, CDCl3) δ202.4,169.7,82.5,69.8,57.6,52.5,29.4,26.4,16.3.

[0077] The mass spectrometry analysis data are as follows:

[0078] HRMS (ESI / [M+Na] + ); The theoretical calculated data of high resolution electrospray ionization mass spectrometry is C8H9BrO2:238.9678, and the actual measured value is 238.9674 (HRMS(ESI / [M+Na] + )calculated for C8H9BrO2:238.9678found238.9674).

[0079] In thin layer chromatography (TLC), TLC result: Rf=0.3 (EA / Hex=1:10).

[0080] Step 2: Preparation of 2-bromo-4-allylanisole. The chemical reaction formula for the preparation of 2-bromo-4-allylanisole is as follows:

[0081]

[0082] B1. Allyl anisole (14.84 g, 100 mmol), acetic acid (300 mL) and a portion of pyridinium tribromide (42.24 g, 132 mmol) were added to a reactor in sequence. The mixture was reacted at room temperature for 30 minutes, and then the remaining pyridinium tribromide (42.24 g, 132 mmol) was added and the reaction was continued for 23 hours. After the reaction was completed, most of the acetic acid was removed by rotary evaporation to obtain a red liquid. The structural formula of allyl anisole is shown in Formula 4.

[0083] B2. Dilute the red liquid with toluene, wash with a saturated aqueous solution of sodium bicarbonate and then with an aqueous solution of sodium thiosulfate, separate the liquids, and then dry the organic phase with anhydrous sodium sulfate and concentrate to obtain a brown oily liquid;

[0084] B3. The oily liquid obtained in step B1 was dissolved in ether (200 mL), and zinc powder (5.84 g, 88 mmol) and acetic acid (5 mL) were added. After refluxing for 3-5 hours, the mixture was cooled to room temperature and reacted for 22-24 hours. After the reaction, the reactant was filtered, and the filtrate was washed with saturated sodium bicarbonate solution, dried over anhydrous sodium sulfate, and concentrated to obtain a crude product. The crude product was separated by silica gel column chromatography (silica gel, Hex / EA=100:1) to obtain 8.8 g of a colorless oily liquid, namely 2-bromo-4-allylanisole, with a yield of 40%; 2-bromo-4-allylanisole is shown in Formula 5, which has the following NMR spectral characteristics:

[0085] 1 H NMR(400MHz, CDCl3) δ7.20(d,J=7.7Hz,1H),6.77(dd,J=7.7,1.5Hz,1H),6.50(t,J=1.8Hz,1H),6.0 0-5.88(m,1H),5.10(dq,J=8.3,1.5Hz,1H),5.06(t,J=1.4Hz,1H),3.84(s,3H),2.95-2.79(m,2H);

[0086] 13 C NMR (100MHz, CDCl3) δ144.0,141.4,137.0,129.0,126.1,122.0,120.5,111.3,55.2,34.3.

[0087] The mass spectrometry analysis data are as follows:

[0088] HRMS (ESI / [M+Na] + ) High-resolution electrospray ionization mass spectrometry theoretical calculation data is C 10 H 11 BrO: 248.9985, the actual measured value is 248.9983 (HRMS (ESI / [M+Na]+) calculated for C 10 H 11 BrO:248.9985, found 248.9983.).

[0089] Step 3: Prepare a dicarbonyl compound with a floral and fruity aroma, wherein the dicarbonyl compound with a floral and fruity aroma is 2-acetyl-3-(5-allyl-2-methoxyphenyl)-2-cyclopentene-1-carboxylic acid methyl ester; the chemical reaction formula for the preparation of 2-acetyl-3-(5-allyl-2-methoxyphenyl)-2-cyclopentene-1-carboxylic acid methyl ester is as follows:

[0090]

[0091] C1. Palladium catalyst XPhos Pd G3 (67.6 mg, 80 μmol), lithium hydroxide (144 mg, 6 mmol), dried 4A molecular sieves (3.2 g), and DCE (20 mL) were added to the reactor in sequence, and the argon atmosphere was replaced. Then, the reaction substrates 2-acetylhex-5-ynoic acid methyl ester (1.0 g, 6 mmol) and 2-bromo-4-allylanisole (0.9 g, 4 mmol) were quickly added to the reactor, and the temperature was raised to 50° C. for reaction for 24 hours.

[0092] C2. After the reaction, the reactant obtained in step C1 was diluted with DCM (100 mL), and then solid ammonium chloride was added and stirred for 10 minutes, followed by the addition of solid anhydrous sodium sulfate and stirring for 8-12 minutes, and then filtered through diatomaceous earth; the obtained filtrate was directly concentrated under reduced pressure and separated by silica gel column chromatography (silica gel, Hex / EA=10:1) to obtain 0.97 g of a colorless liquid, namely 2-acetyl-3-(5-allyl-2-methoxyphenyl)-2-cyclopentene-1-carboxylic acid methyl ester, in a yield of 78%.

[0093] The 2-acetyl-3-(5-allyl-2-methoxyphenyl)-2-cyclopentene-1-carboxylic acid methyl ester prepared in this example has the following NMR spectral characteristics:

[0094] 1H NMR (400MHz, CDCl3) δ7.20(d,J=7.7Hz,1H),6.77(dd,J=7.7,1.5Hz,1H),6.74-6.71(m,1H),6.50(t,J=1.8Hz,1H),6.00-5.88(m,1H),5.10(d q,J=8.3,1.5Hz,1H),5.06(t,J=1.4Hz,1H),3.84(s,3H),3.73(s,3H), 3.39-3.36(m,2H),2.95-2.79(m,2H),2.54-2.41(m,2H),2.23(s,3H);

[0095] 13 C NMR (125MHz, CDCl3) δ204.1,172.4,157.8,144.0,141.4,137.0,129.0,12 6.1,122.0,120.5,116.1,111.3,74.2,55.2,52.4,40.2,34.3,29.5,26.

[0096] The mass spectrometry analysis data are as follows:

[0097] HRMS (ESI / [M+Na] + ) High-resolution electrospray ionization mass spectrometry theoretical calculation data is C 19 H 22 O4:337.1410, the actual measured value is 337.1408 (HRMS (ESI / [M+Na] + )calculated for C 19 H 22 O4:337.1410,found337.1408.).

[0098] FTIR (Fourier transform infrared spectroscopy) data are as follows:

[0099] FTIR(DCM)1739(C=O),1710(C=O),1253(CO),1219(CO)cm -1 .

[0100] In thin layer chromatography (TLC), TLC result: Rf=0.4 (EA / Hex=1:10).

[0101] Example 2

[0102] The methyl 2-acetyl-3-(5-allyl-2-methoxyphenyl)-2-cyclopentene-1-carboxylate prepared in Example 1 was subjected to aroma rating, fragrance retention test, and fragrance base aroma test. The test results are as follows:

[0103] (1) Aroma evaluation: 14 perfumers with more than 5 years of work experience gave the following evaluation on the aroma of the compound: All 14 perfumers agreed that in addition to presenting a special tropical floral and fruity aroma, the compound also has a special aromatic aroma with a lilac fragrance.

[0104] (2) Fragrance retention test: 2-acetyl-3-(5-allyl-2-methoxyphenyl)-2-cyclopentene-1-carboxylic acid methyl ester was prepared into a propylene glycol solution with a mass fraction of 10%. A scent test paper was taken and dipped in an appropriate amount of the solution. The test paper was placed on a scent rack and three perfumers smelled the scent once every two hours. When two or more perfumers could not perceive the fragrance of the scent test paper, the fragrance retention time was recorded.

[0105] The fragrance lasting test shows that the special tropical floral and fruity aroma of 2-acetyl-3-(5-allyl-2-methoxyphenyl)-2-cyclopentene-1-carboxylic acid methyl ester has a lasting time of 60 hours, and the special aromatic smell and lilac fragrance has a lasting time of 72 hours.

[0106] (3) Fragrance base aroma test: The formula of fruity fragrance base is shown in the following table:

[0107]

[0108] According to the formula in the above table, fragrance base A and fragrance base B were prepared. The parts of each raw material in the table are by weight. Unlike fragrance base A, fragrance base B was added with 50 parts of the target product of the present invention, 2-acetyl-3-(5-allyl-2-methoxyphenyl)-2-cyclopentene-1-carboxylic acid methyl ester. 9 perfumers unanimously agreed that fragrance base B had a more prominent and special tropical floral and fruity aroma than fragrance base A, with a more prominent characteristic aromatic aroma and a slightly elegant lilac fragrance, and the aroma quality of the fragrance base was significantly improved.

[0109] The above embodiments are preferred implementation schemes of the present invention. In addition, the present invention can also be implemented in other ways. Any obvious replacement without departing from the concept of the present invention is within the scope of protection of the present invention.

Claims

1. A dicarbonyl compound having a floral or fruity aroma, characterized in that: It has the following structural formula:

2. A method for preparing a dicarbonyl compound having a floral and fruity aroma as claimed in claim 1, characterized in that: The steps include: Step 1: Using methyl acetoacetate and iodide as raw materials, prepare methyl 2-acetylhex-5-ynoate. The structural formula of the iodide is shown below: The structural formula of methyl 2-acetylhex-5-ynoate is shown below: Step 2: Using allyl anisole as a raw material, prepare 2-bromo-4-allyl anisole. The structural formula of allyl anisole is shown below: The structural formula of 2-bromo-4-allylanisole is shown below: Step 3: Using the 2-acetylhex-5-ynoic acid methyl ester prepared in step 1 and the 2-bromo-4-allylanisole prepared in step 2 as raw materials, and after separation and purification, obtaining a dicarbonyl compound with a floral and fruity aroma, wherein the dicarbonyl compound with a floral and fruity aroma is 2-acetyl-3-(5-allyl-2-methoxyphenyl)-2-cyclopentene-1-carboxylic acid methyl ester.

3. The method for preparing a dicarbonyl compound having a floral and fruity aroma according to claim 2, wherein: In the step 1, the preparation method of methyl 2-acetylhex-5-ynoate comprises the following steps: A1. Place kerosene-coated sodium hydride in a reaction vessel, add anhydrous THF to dissolve, cool to -1-1°C, then slowly add methyl acetoacetate, stir in an ice bath for 0.2-0.8 hours, until no obvious bubbles are generated, then add iodide, and heat to 55-65°C for 70-74 hours; A2. After the reaction is completed, the mixture is cooled to room temperature, saturated aqueous ammonium chloride solution is added to quench the reaction, the organic phase is separated, and the residual organic phase is extracted from the aqueous phase with ethyl acetate; the combined organic phase is dried and concentrated, and then separated by column chromatography to obtain a light yellow oily liquid, i.e., 2-acetylhex-5-ynoic acid methyl ester.

4. The method for preparing a dicarbonyl compound having a floral and fruity aroma according to claim 3, wherein: In step A1, 180-220 mmol of sodium hydride wrapped in kerosene is placed in a reaction vessel, 580-620 mL of anhydrous THF is added for dissolution, and the mixture is cooled to -1-1°C. 180-220 mmol of methyl acetoacetate is then slowly added, and the mixture is stirred in an ice bath for 0.2-0.8 hours until no obvious bubbles are generated. 200-208 mmol of iodide is then added, and the mixture is heated to 55-65°C for 70-74 hours.

5. The method for preparing a dicarbonyl compound having a floral and fruity aroma according to claim 2, wherein: In the step 2, the preparation method of 2-bromo-4-allylanisole comprises the following steps: B1, allyl anisole, acetic acid and part of the pyridinium tribromide salt were added to the reactor in sequence, and the reaction was carried out at room temperature for 25-35 minutes, and then the remaining pyridinium tribromide salt was added and the reaction was continued for 22-24 hours. After the reaction was completed, most of the acetic acid was removed by rotary evaporation to obtain a red liquid; B2. Dilute the red liquid with toluene, wash with a saturated aqueous solution of sodium bicarbonate and then with an aqueous solution of sodium thiosulfate, separate the liquids, and then dry the organic phase with anhydrous sodium sulfate and concentrate to obtain a brown oily liquid; B3. The oily liquid obtained in step B1 was dissolved in ether, zinc powder and acetic acid were added, and the mixture was refluxed for 3-5 hours, cooled to room temperature, and reacted for 22-24 hours. After the reaction, the reactant was filtered, and the filtrate was washed with saturated sodium bicarbonate solution, dried over anhydrous sodium sulfate, and concentrated to obtain a crude product. The crude product was separated by silica gel column chromatography to obtain a colorless oily liquid, thereby preparing 2-bromo-4-allylanisole.

6. The method for preparing a dicarbonyl compound having a floral and fruity aroma according to claim 5, wherein: In the step B1, 80-120 mmol of allylanisole, 280-320 mL of acetic acid, and a portion of 130-134 mmol of pyridinium tribromide are sequentially added to a reactor, and the mixture is reacted at room temperature for 25-35 minutes. The remaining 130-134 mmol of pyridinium tribromide is then added and the reaction is continued for 22-24 hours. After the reaction is completed, most of the acetic acid is removed by rotary evaporation to obtain a red liquid.

7. The method for preparing a dicarbonyl compound having a floral and fruity aroma according to claim 5, wherein: In step B3, the oily liquid obtained in step B1 is dissolved in 180-220 mL of ether, 5-6 g of zinc powder and 3-8 mL of acetic acid are added, and the mixture is refluxed for 3-5 hours, cooled to room temperature, and reacted for 22-24 hours. After the reaction is completed, the reactant is filtered, and the filtrate is washed with a saturated sodium bicarbonate solution, dried over anhydrous sodium sulfate, and concentrated to obtain a crude product. The crude product is separated by silica gel column chromatography to obtain a colorless oily liquid, thereby preparing 2-bromo-4-allylanisole.

8. The method for preparing a dicarbonyl compound having a floral and fruity aroma according to claim 2, wherein: In the step 3, the preparation method of methyl 2-acetyl-3-(5-allyl-2-methoxyphenyl)-2-cyclopentene-1-carboxylate comprises the following steps: C1. Palladium catalyst XPhos Pd G3, lithium hydroxide, dried 4A molecular sieves, and DCE were sequentially added to a reactor, and argon protection was replaced. Then, the reaction substrates 2-acetylhex-5-ynoic acid methyl ester and 2-bromo-4-allylanisole were quickly added to the reactor, and the temperature was raised to 45-55° C. and the reaction was carried out for 23-25 ​​hours. C2. After the reaction, the reactant obtained in step C1 was diluted with DCM, and then solid ammonium chloride was added and stirred for 8-12 minutes, and then solid anhydrous sodium sulfate was added and stirred for 8-12 minutes, and then filtered through diatomaceous earth; the obtained filtrate was directly concentrated under reduced pressure and separated by silica gel column chromatography to obtain a colorless liquid, that is, 2-acetyl-3-(5-allyl-2-methoxyphenyl)-2-cyclopentene-1-carboxylic acid methyl ester was prepared.

9. The method for preparing a dicarbonyl compound having a floral and fruity aroma according to claim 8, wherein: In step C1, 75-85 μmol of palladium catalyst XPhos Pd G3, 4-8 mmol of lithium hydroxide, 3.0-3.4 g of dried 4A molecular sieves, and 18-22 mL of DCE are added to a reactor in sequence, and argon protection is replaced; then, the reaction substrate 4-8 mmol of methyl 2-acetylhex-5-ynoate and 2-6 mmol of 2-bromo-4-allylanisole are quickly added to the reactor, and the temperature is raised to 45-55° C. and the reaction is carried out for 23-25 ​​hours.

10. A floral and fruity fragrance base, characterized by: The invention comprises the following raw materials in parts by weight: 45-55 parts of methyl 2-acetyl-3-(5-allyl-2-methoxyphenyl)-2-cyclopentene-1-carboxylate, 8-12 parts of cyclopentyl ester, 12-18 parts of ethyl methyl naphthalene ketone, 28-32 parts of geraniol, 42-48 parts of farnesol, 3-8 parts of geranyl acetate, 12-16 parts of anisaldehyde, 18-22 parts of isovalerate, 12-16 parts of lemon oil terpenes, 76-84 parts of gamma-caprolactone, 22-28 parts of linalyl acetate, 18-22 parts of isomethyl ionone, 6-10 parts of allyl hexanoate, 18-22 parts of ethyl heptanoate, 6-10 parts of neral, 8-12 parts of damascenone and 600-700 parts of propylene glycol.

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