A 2,3-dihydro-3-hydroxy-6-methyl-4H-pyran-4-one-5-O-carbonate and its applications

Abstract

This invention relates to a 2,3-dihydro-3-hydroxy-6-methyl-4H-pyran-4-one-5-O-carbonate triester and its applications. Using 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one as a raw material, the 2,3-dihydro-3-hydroxy-6-methyl-4H-pyran-4-one-5-O-carbonate triester is prepared via esterification. This compound exhibits good storage stability and flavoring stability. When added to cigarettes, it can decompose and release 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one and maltol, significantly enhancing the "sweet aftertaste" of cigarette smoke and highlighting the "sweet" and "smooth" taste characteristics of cigarettes. Compared with 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one, it can also increase the caramel-like aroma of the smoke, enriching the tobacco aroma and enhancing the overall flavor of cigarettes, thus possessing potential application value.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of cigarette flavor synthesis, and particularly relates to 2,3-dihydro-3-hydroxy-6-methyl-4H-pyran-4-ketone-5-O-carbonic acid triester and application thereof as a flavor in cigarettes. BACKGROUND

[0002] The smoke "sweetness" is a key index affecting the sensory quality and style characteristics of cigarettes and is one of important signs distinguishing Chinese cigarettes from American, British and Japanese cigarettes. 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-ketone belongs to pyran enol ketone compounds and is commonly present in cigarette smoke, Maillard reaction products, sugar cleavage products and natural extracts; it is significantly positively correlated with the smoke "sweetness" and can obviously improve the sweet taste of cigarette smoke and highlight the "sweet" and "moist" taste characteristics of cigarettes.

[0003] However, 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-ketone (DDMP) has poor storage stability and has not been applied in cigarettes so far. It is of great significance for the development of new cigarette flavors to purposefully modify the structure of 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-ketone, enhance its flavor characteristics in some aspects and eliminate or weaken its adverse influencing factors. SUMMARY

[0004] The application aims to provide 2,3-dihydro-3-hydroxy-6-methyl-4H-pyran-4-ketone-5-O-carbonic acid triester and application thereof as a flavor in cigarettes, so as to solve the problems of poor stability, easy deterioration and damage and inability to be used as a sweet flavor raw material of DDMP.

[0005] The application is implemented by the following technical scheme:

[0006] 2,3-dihydro-3-hydroxy-6-methyl-4H-pyran-4-ketone-5-O-carbonic acid triester, the structural formula of which is as follows:

[0007]

[0008] The preparation method of the above-mentioned 2,3-dihydro-3-hydroxy-6-methyl-4H-pyran-4-ketone-5-O-carbonic acid triester comprises the following steps:

[0009] 1) In a reaction bottle, chloroformic acid trichloromethyl ester and an organic solvent are added, and the reaction bottle is cooled to-5-5 DEG C under nitrogen protection;

[0010] 2) at the temperature of step 1), slowly drop the mixture of 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one, catalyst, organic base and organic solvent, raise the temperature to 30-80℃ and react for 6-20h;

[0011] 3) after the reaction, wash the organic mixture with saturated sodium chloride solution, dry with anhydrous sodium sulfate, evaporate the solvent under reduced pressure, and separate the crude product by silica gel column chromatography to obtain 2,3-dihydro-3-hydroxy-6-methyl-4H-pyran-4-one-5-O-triester (DDMP triester).

[0012] Further, the organic solvent in step 1) and step 2) is one of chloroform, toluene, acetonitrile, tetrahydrofuran or cyclohexane.

[0013] Further, the catalyst in step 2) is one of 2-dimethylaminopyridine, 2-diethylaminopyridine or 4-dimethylaminopyridine.

[0014] Further, the organic base in step 2) is one of piperidine, potassium tert-butoxide or DBU (1,8-diazabicycloundec-7-ene).

[0015] Further, the molar ratio of 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one, catalyst, organic base and chloroformic acid trichloromethyl ester in step 2) is 1:(0.05-0.2):(1-2):(0.15-0.5).

[0016] The application of 2,3-dihydro-3-hydroxy-6-methyl-4H-pyran-4-one-5-O-triester, the 2,3-dihydro-3-hydroxy-6-methyl-4H-pyran-4-one-5-O-triester of any one of the above is applied to cigarettes.

[0017] Further, the alcohol solution of 2,3-dihydro-3-hydroxy-6-methyl-4H-pyran-4-one-5-O-triester is sprayed on the tobacco.

[0018] Further, the addition amount of 2,3-dihydro-3-hydroxy-6-methyl-4H-pyran-4-one-5-O-triester is 1-50ppm of the mass of tobacco.

[0019] The beneficial effects of the present application are:

[0020] This technical solution uses 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one as a raw material to prepare 2,3-dihydro-3-hydroxy-6-methyl-4H-pyran-4-one-5-O-carbonate (DDMP tricarbonate) by reacting it with trichloromethyl chloroformate. This type of compound exhibits good storage and flavoring stability. When added to cigarettes, it not only enhances the oral sweetness and improves the aftertaste comfort of 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one, but also increases the caramel-like aroma and smoothness of the smoke, thus improving the overall aroma and character of the cigarette, demonstrating its potential application value. Detailed Implementation

[0021] The technical solutions of the present invention will be described in detail below through embodiments. The following embodiments are merely exemplary and can only be used to explain and illustrate the technical solutions of the present invention, and should not be construed as limiting the technical solutions of the present invention.

[0022] Example 1

[0023] 0.79 g (4 mmol) of chloroformate was dissolved in 20 mL of anhydrous chloroform. The solution was cooled to 0 °C, and a chloroform solution of DDMP (2.88 g (20 mmol), 2-dimethylaminopyridine (0.12 g (1 mmol)) and piperidine (2.13 g (25 mmol) was slowly added dropwise. The mixture was then heated to 50 °C and reacted for 16 h. The organic phase was washed once with saturated sodium chloride, dried over anhydrous Na2SO4, and the solvent was removed by evaporation. The residue was subjected to silica gel column chromatography to give 2.42 g of 2,3-dihydro-3-hydroxy-6-methyl-4H-pyran-4-one-5-O-carbonate as a white solid, with a yield of 74.9%.

[0024] Example 2

[0025] 0.79 g (4 mmol) of trichloromethyl chloroformate was dissolved in 20 mL of anhydrous acetonitrile. The solution was cooled to 0 °C, and a solution of DDMP (2.88 g (20 mmol), 4-dimethylaminopyridine (0.12 g (1 mmol)) and DBU (3.80 g (25 mmol) in acetonitrile was slowly added dropwise. The solution was then heated to 60 °C and reacted for 20 h. The organic phase was washed once with saturated sodium chloride, dried over anhydrous Na2SO4, and the solvent was removed by evaporation. The residue was subjected to silica gel column chromatography to give 2.68 g of 2,3-dihydro-3-hydroxy-6-methyl-4H-pyran-4-one-5-O-carbonate as a white solid, with a yield of 83.0%.

[0026] Example 3

[0027] 0.99 g (5 mmol) of trichloromethyl chloroformate was dissolved in 20 mL of anhydrous toluene. The solution was cooled to 0 °C, and a toluene solution of DDMP (2.88 g (20 mmol), 4-dimethylaminopyridine (0.24 g (2 mmol)) and potassium tert-butoxide (2.81 g (25 mmol) was slowly added dropwise. The mixture was then heated to 60 °C and reacted for 16 h. The organic phase was washed once with saturated sodium chloride, dried over anhydrous Na₂SO₄, and the solvent was evaporated. The residue was subjected to silica gel column chromatography to give 2.48 g of a white solid, 2,3-dihydro-3-hydroxy-6-methyl-4H-pyran-4-one-5-O-carbonate, in 76.8% yield.

[0028] Example 4

[0029] 0.99 g (5 mmol) of trichloromethyl chloroformate was dissolved in 20 mL of anhydrous tetrahydrofuran. The solution was cooled to 0 °C, and a tetrahydrofuran solution of DDMP (2.88 g, 20 mmol), 2-diethylaminopyridine (0.30 g, 2 mmol), and potassium tert-butoxide (2.81 g, 25 mmol) was slowly added dropwise. The mixture was then heated to 80 °C and reacted for 20 h. The organic phase was washed once with saturated sodium chloride, dried over anhydrous Na₂SO₄, and the solvent was evaporated. The residue was subjected to silica gel column chromatography to give 2.08 g of a white solid, 2,3-dihydro-3-hydroxy-6-methyl-4H-pyran-4-one-5-O-carbonate, with a yield of 64.4%.

[0030] Fragrance performance testing:

[0031] Weigh out a certain amount of 2,3-dihydro-3-hydroxy-6-methyl-4H-pyran-4-one-5-O-carbonate (DDMP tricarbonate) and 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP) prepared in any of the above embodiments, and dilute them with ethanol to prepare a 5% solution for later use. Weigh 100g of unflavored and unadded blank cigarette tobacco, spread it evenly on a clean tray, and spray DDMP tricarbonate and DDMP solution evenly on the tobacco to obtain DDMP tricarbonate and DDMP-to-tobacco specific gravities of 5ppm, 10ppm, 20ppm, 30ppm and 50ppm respectively. Seal and place for 4 hours, dry in an oven at 50℃, humidify with distilled water to standard moisture content (12%), roll into standard cigarettes, and balance the moisture content (humidity 60%±2%, temperature 22±1℃) for 48 hours before evaluation smoking. The control sample was a blank cigarette, which was equilibrated for 48 hours under the same temperature and humidity conditions.

[0032] Table 1. Evaluation results of DDMP tricarbonate and DDMP flavoring

[0033]

[0034]

[0035] Table 1 shows that both DDMP tricarbonate and DDMP significantly enhance the "sweetness" of cigarette smoke, highlighting the "sweet" and "smooth" taste characteristics, improving and modifying the aroma, reducing irritation, improving the flavor, and making the aftertaste clean and comfortable. Compared to DDMP, DDMP tricarbonate can also increase the caramel-like aroma and smoothness of the smoke, enhancing the overall aroma and quality of the cigarette, showing potential application value. However, DDMP tricarbonate levels exceeding 30 ppm result in a cloying sweetness and a burnt, dry aroma, affecting the aroma and quality of the smoke, worsening the aftertaste, and causing discomfort. Recommended dosage: 10–30 ppm.

[0036] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. 2,3-dihydro-3-hydroxy-6-methyl-4H-pyran-4-one-5-O-carbonic acid triester, characterized in that, The structural formula is: The preparation method comprises the following steps: 1) adding trichloromethyl chloroformate and an organic solvent in a reaction bottle, and cooling to -5-5 ℃ under nitrogen protection; 2) slowly adding a mixture of 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one, a catalyst, an organic base and an organic solvent at the temperature of step 1), and reacting at 30-80 ℃ for 6-20 h; 3) after the reaction is completed, the organic mixture is washed with a saturated sodium chloride solution, dried with anhydrous sodium sulfate, and the solvent is removed under reduced pressure; the crude product is separated by silica gel column chromatography to obtain DDMP triseter; The molar ratio of 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one, the catalyst, the organic base and trichloromethyl chloroformate in step 2) is 1:(0.05-0.2):(1-2):(0.15-0.5).

2. The 2,3-dihydro-3-hydroxy-6-methyl-4H-pyran-4-one-5-O-carbonic acid triester according to claim 1, characterized in that, The organic solvent in steps 1) and 2) is one of trichloromethane, toluene, acetonitrile, tetrahydrofuran or cyclohexane.

3. The 2,3-dihydro-3-hydroxy-6-methyl-4H-pyran-4-one-5-O-carbonic acid triester according to claim 1, characterized in that, The catalyst in step 2) is one of 2-dimethylaminopyridine, 2-diethylaminopyridine or 4-dimethylaminopyridine.

4. The 2,3-dihydro-3-hydroxy-6-methyl-4H-pyran-4-one-5-O-carbonic acid triester according to claim 1, characterized in that, The organic base in step 2) is one of piperidine, potassium tert-butoxide or 1,8-diazabicycloundec-7-ene.

5. Use of 2,3-dihydro-3-hydroxy-6-methyl-4H-pyran-4-one-5-O-carbonic triester, characterized in that, The application of 2,3-dihydro-3-hydroxy-6-methyl-4H-pyran-4-one-5-O-triseter in any of the above in cigarettes.

6. Use of 2,3-dihydro-3-hydroxy-6-methyl-4H-pyran-4-one-5-O-carbonic acid triester according to claim 5, characterized in that, An alcohol solution of 2,3-dihydro-3-hydroxy-6-methyl-4H-pyran-4-one-5-O-triseter is sprayed on tobacco.

7. The 2,3-dihydro-3-hydroxy-6-methyl-4H-pyran-4-one-5-O-triseter according to claim 6, wherein the addition amount of the 2,3-dihydro-3-hydroxy-6-methyl-4H-pyran-4-one-5-O-triseter is 1-50 ppm of the mass of tobacco.

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