JPS6045876B2 - Method for producing 2-hydroxy-5-pentyltetrahydrofuran - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to 2-hydroxy-5-pentyltetrahydrofuran (γ-nonalactol) represented by the following formula Concerning the manufacturing method.

The present inventors have conducted research on aroma and flavor components of watermelon.

As a result, we succeeded in extracting and separating from natural watermelon the compound of formula (1), which was previously completely unknown and undescribed as an aroma or flavor component of watermelon, as a key flavor of watermelon's aroma or flavor. Furthermore, it has been discovered that the compound represented by the above formula (1) can be synthesized. Furthermore, the formula (
1) The compound has a fresh green note or a sweet fresh green note and has excellent persistence as a unique fruity and green aroma or flavor imparting or modulating agent, thus making it suitable for use in foods and beverages. (contains luxury goods),
It has been discovered that it is useful as an excellent long-lasting aroma or flavor imparting or modulating agent in a wide range of applications such as cosmetics, health care, hygiene, and pharmaceuticals. For the same applicant, the above formula (
1) Including the compound, the following formula (2), R, R (A) However, in the formula, R represents a hydrogen atom or a group R', and here R2 is an alkyl group, an alkenyl group, and an arylalkyl group. 2-substituted- represented by a group selected from the group consisting of
A novel compound represented by a 5-alkyl-tetrahydrofuran derivative, its production method, and its use have already been proposed in Japanese Patent Application No. 81264/1982.

5 The present inventors synthesized the compound of formula (1) included in formula (2) above using a different synthesis method from the above proposal.
We have discovered an alternative method that can be industrially advantageously produced with high purity and high yield through easy operations.

Therefore, the present invention provides an alternative method for producing the novel compound 2-hydroxy-5-pentyl-tetrahydrofuran of formula (1).

According to the method of the present invention, 2-hydroxy-5- of the above formula 1
Pentyltetrahydrofuran is expressed by the formula (
By bringing 1-decen-5-ol (2) into contact with ozone and reductively decomposing the product in the presence of a reducing agent, it can be easily produced with high purity and high yield.

The raw material 1-decen-5-ol of the above formula (2) can be formed, for example, by bringing 1-decen-5-one of the formula (3) into contact with a reducing agent, as shown in the diagram below, and the raw material 1-decen-5-ol of the formula (3) The compound can be formed, for example, by contacting the alkyl 3-oxooctanoate of the formula (5) with the allyl halide of the formula (4) in the presence of a base, followed by saponification and decarboxylation. can.

In the above formula, R1 represents a lower alkyl group, and x represents a halogen atom.

Hereinafter, the production of the compound of formula (1) of the present invention will be explained in more detail using the embodiment shown in the above diagram as an example.

The alkyl 3-oxooctanoate of the above formula (5) can be easily produced in good yield and purity by a known method of reacting 2-heptanone with dialkyl carbonate in the presence of a base, and is Specific examples include C1-C6 lower alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl and the like.

1-decen-5-one of the above formula (3) can be obtained, for example, by contacting the alkyl 3-oxooctanoate of the above formula (5) with the allyl halide of the above formula (4) in the presence of a base, and further, It can be easily formed in good yield by saponification and decarboxylation. The condensation reaction in which the compound of formula (4) is brought into contact can be carried out, for example, in an inert organic solvent at a temperature of about 0 tm to 0 tm.
It can be carried out at a temperature of about 100° C., preferably about 10° C. to about 30° C., for about 3 to about ω hours. Specific examples of the base used in the condensation reaction with the compound of formula (4) include, for example, sodium methoxide,
Sodium ethoxide, sodium propoxide, sodium isopropoxide, sodium t-butoxide,
potassium methoxide, potassium ethoxide, potassium t
-butoxide, sodium hydride, potassium hydride, lithium hydride, sodium amide, potassium amide, lithium amide, butyl lithium, lithium dialkylamides, and the like.

The amount of these bases to be used is about 1 to about 3 mol per 1 mol of the compound of formula (5) as a raw material, which is sufficient, and more preferably about 1 to about 1.5 mol is often adopted. .
Examples of the allyl halide of formula (4) used in the condensation reaction include allyl chloride, allyl bromide, and allyl iodide, and the amounts of these to be used can be selected as appropriate.

For example, about 1 to about 3 mol is often employed per 1 mol of the compound of formula (5) as a raw material.

Further, specific examples of the inert organic solvent used in the above condensation reaction include methanol, ethanol,
propanol, isopropyl alcohol, butanol,
t-Butyl alcohol, tetrahydrofuran, ether, 1,2-dimethoxyethane, dioxane, benzene,
Examples include toluene, xylene, liquid ammonia, dimethyl sulfoxide, and the like. These solvents can be used alone or in combination of two or more. There are no special restrictions on the amount of these solvents used, but the raw material formula (5
) The amount used is preferably about 2 to about 10 times the heel volume, more preferably about 3 to about 1 times the saliva volume, based on the compound. After bringing the compound of formula (5) into contact with the allyl halide of formula (4) as described above,
Saponification and decarboxylation reactions can be carried out by conventional methods.

For example, the condensation reaction product formed as described above can be saponified and decarboxylated by refluxing in the presence of an acid. Saponification can be carried out, for example, by contacting with a basic catalyst such as caustic soda or caustic potash to cause hydrolysis. For decarboxylation, for example, heat with hydrochloric acid and observe the generation of carbon dioxide gas until it stops.
This can be easily done by refluxing. After saponification and decarboxylation reactions, for example, the reaction product is poured into water, neutralized, extracted with an appropriate solvent, the solvent layer is washed with water, dried, and concentrated to obtain the formula (3). 1-decen-5-one represented by ) can be obtained with high yield and high purity. If desired, further purification can be carried out, for example, by means such as vacuum distillation or column chromatography. The 1-decen-5-ol of the formula (2) is, for example, the 1-decene-5-ol of the formula (3) that can be formed as described above.
can be easily carried out in good yield and selectivity by contacting with a suitable reducing agent, for example in an inert organic solvent.

The reaction temperature of the reaction can be selected as appropriate, for example, about -20
A temperature range of about 100°C to about 100°C, more preferably about 0 to about 30°C, can be exemplified.

The reaction time can be appropriately changed depending on the reaction temperature and the like, and can be exemplified by a reaction time of about 1 to about 1 hour. Examples of reducing agents used in the above reduction reaction include metal hydrides such as lithium aluminum hydride and sodium borohydride; metal alcoholates such as aluminum isopropoxide;
etc. can be exemplified.

Specific examples of the inert organic solvent include methanol, ethanol, propanol, isopropyl alcohol, butanol, water, ether, tetrahydrofuran, dioxane, benzene, hexane, petroleum ether, and pentane. . These solvents can be used alone or in combination of two or more. There is no particular restriction on the amount of these solvents used, but if the above formula (
3) The amount used may be about 1 to about 5 times the amount of saliva, more preferably about 2 to about 1 times the amount of rutting, relative to the compound. After the completion of the above reaction, for example, by injecting the reaction product into water or removing the catalyst, extracting with a suitable solvent, washing the solvent layer with water, drying, and concentrating, the formula (2) can be obtained. The expressed 1-decen-5-ol can be obtained in high yield and high purity. If desired, further purification can be carried out by means such as vacuum distillation or column chromatography. According to the method of the present invention, the reaction of oxidizing the compound of formula (2), which can be formed as described above, by contacting it with ozone and reductively decomposing the ozonide produced, can be carried out in the presence or absence of a solvent. It can be carried out. The contact with ozone is preferably carried out at a low temperature, for example, from about -78°C to about +30°C, more preferably from about -78°C to about -30°C. can.

The reaction time can also be changed as appropriate depending on the flow rate of ozone used, the reaction temperature, etc., and can be exemplified by a reaction time of about 10 to about 3 hours. The amount of ozone used in the above reaction can also be appropriately selected. For example, the formula (
Approximately 0.8 per mole of 1-decene-5-ol in 2)
Examples include amounts of from about 1.5 moles to about 1.5 moles.

Specific examples of the solvent used in the embodiment in which contact with ozone is carried out in the presence of a solvent include pentane, hexane, cyclohexane, benzene, carbon tetrachloride, chloroform, methylene dichloride, methylene chloride, ether, tetrahydrofuran, Examples include inert organic solvents such as ethyl acetate, acetone, nitromethane, formaldehyde and the like; active solvents such as formic acid, acetic acid, propionic acid, methanol, ethanol, propanol, water and the like.

These solvents can be used alone or in combination of two or more. There is no particular restriction on the amount of these solvents used, but the amount used is about 2 to about 200 times the weight of the compound of formula (2), more preferably about 10 to about 3 times the amount by weight. I can give an example. Further, specific examples of the reducing agent used in the reductive decomposition reaction using the above reducing agent include:
Examples include zinc dust, triphenylphosphine, dimethyl sulfide, sodium iodide, ferrous sulfate, and catalytic hydrogenation catalysts.

The amount of these reducing agents to be used can be selected as appropriate; for example, about 1 to about 40 moles per mole of the compound of formula (2) is sufficient, and more preferably about 1 to about 10 moles. often adopted. Furthermore, the reaction temperature of the above reductive decomposition reaction can be selected as appropriate, for example, from about -30 to about 120
The reaction temperature can be exemplified by a temperature range of about 0.degree. C., more preferably about -10 to about 0.degree. The reaction time can be changed as appropriate depending on the reaction temperature, etc., for example,
An example of a reaction time is about 1 to about 5 hours. After the reaction is completed, for example, the reaction product is injected into water,
By drying and concentrating, the desired compound, formula (
1) 2-hydroxy-5-pentyltetrahydrofuran can be obtained with high purity and high yield.

Furthermore, if desired, further purification can be carried out using means such as vacuum distillation or column chromatography. The compound of formula (1) obtainable as described above has a boiling point of about 95 to about 98°C/47rfmHg. ．． nBa0=1.
No. 4475 is an oily substance that is extremely useful as a persistent aroma or flavor imparting or modulating agent.

The compound of formula (1) has a fresh green note or a sweet fresh green note, and has excellent persistence and unique aroma or flavor as a component of fruit-based and green-based aroma or flavor compositions.

Thus, by utilizing the 2-hydroxy-5-pentyl-tetrahydrofuran of the formula (1) obtained by the method of the present invention, there is provided a long-lasting aroma and flavor imparting or modulating agent characterized by containing the compound as an active ingredient. We can provide.Furthermore,
By using this persistent aroma and flavor imparting or modulating agent, the formula (1)
Foods and beverages characterized by containing 2-hydroxy-5-pentyltetrahydrofuran of formula (1) as an aroma component;
Soaps, detergents, cosmetics; 2-hydroxy-5 of formula (1)
- It is possible to provide health care, sanitary, pharmaceutical products, etc. that contain pentyltetrahydrofuran as an aromatic flavor component.

For example, drinks such as juices, fruit alcoholic drinks, milk drinks, lactic acid bacteria drinks, carbonated drinks; frozen desserts such as ice creams and ice cream cakes; Japanese and Western sweets; jams; breads; chewing gum, To provide food and drink products containing various foods, instant beverages, and food products, including favorite foods such as coffee, cocoa, black tea, tea, etc., in an appropriate amount capable of imparting their unique aroma and flavor.

For example, cosmetics containing Jumpu, hair rinses, hair creams, pomades, other hair cosmetic bases; cosmetic soaps and other makeup/facial cleansing bases in an appropriate amount to impart the unique fragrance. can be provided. Furthermore, its unique scent can be used in various health and hygiene products such as laundry detergents, disinfectant detergents, deodorant cleaning products, and other health and hygiene products; It is possible to provide health care and hygienic medicines that are blended or applied in an appropriate amount to impart flavor.

Hereinafter, one embodiment of the method of the present invention will be explained by way of example.
It will be explained in more detail.

Reference Example 1 In a reaction vessel for producing 1-decene-5-one [formula (3)],
Metallic sodium 5.5g (a). 24 mol) and 120 ml of absolute ethyl alcohol were charged, and sodium ethoxide (C2H5ONa) was prepared under reflux.

Next, ethyl 3-oxooctanoate 44f1 (0.24
mol) and stirred and reacted for about 1 hour while refluxing at a temperature of about 80°C. Furthermore, allyl chloride 17.6y (0.23 mol) was added dropwise under reflux for about 4 hours, and the reaction was further stirred for about 3 hours under reflux. After the reaction is completed, it is cooled, the resulting salt precipitate is suctioned and filtered, and the liquid is concentrated. Next, 200 mL of 7.5% sodium hydroxide solution is added and hydrolyzed under reflux for about 2 hours. After hydrolysis, the mixture is made acidic with sulfuric acid, and then decarboxylated under reflux for about 1 hour. After the reaction is completed, the reaction product is neutralized and extracted with a suitable solvent. The extract is washed with alkali, water, dried, and concentrated. The obtained residue was distilled under reduced pressure to obtain pure 1-decen-5-one 25q (boiling point: 95-109°C/22 H
yield of 70%). Reference example 21-Decene-5-
7.9 f (0.21 mol) of sodium borohydride (NaBH4) and 800 ml of 95% ethyl alcohol are charged into a reaction vessel.

Next, while stirring under water cooling, 1-decene-5-one 42
．． Ethyl alcohol solution of 5y (0.28 mol) 200
ml is added dropwise over about 1 hour. After the dropwise addition, the reaction is further stirred at room temperature for about 2 hours. After the reaction is complete, the reaction product is poured into dilute hydrochloric acid and poured out with a suitable solvent. Wash the extract with water, dry it,
Concentrate. By distilling the obtained residue under reduced pressure,
Pure 1-decen-5-ol 37.4y (boiling point: 70
~80°C/3wtHg1 yield 85%). Example 1
500 ml of a methylene chloride solution containing 18.7 g (0.12 mol) of 1-decen-5-ol was charged into a reaction vessel, and at a reaction temperature of -40 to -20°C, ozone gas was added at a rate of 60 mt/Hr. Let's react through this.

Claims (1)

[Claims] 1 1-decen-5-ol represented by the following formula (2) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (2) is brought into contact with ozone, and the product is brought into contact with ozone in the presence of a reducing agent. A method for producing 2-hydroxy-5-pentyltetrahydrofuran represented by the following formula (1), which is characterized by reductive decomposition. There are mathematical formulas, chemical formulas, tables, etc..