JPS6058732B2 - Production method of β-bourbonene - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing β-bourbonene, which has a unique aroma and is used as a fragrance material, using an essential oil containing germacrene D as a raw material.

Conventionally, β- has a unique aroma and is useful as a fragrance material.
As a method for obtaining bourbonene, a synthetic method using cyclopentanone as a raw material [Journal of the American Chemical Society (J, Am, Chem, So.
c,) 9:00, p. 6171 (1968)], a photoreaction synthesis method of germacrene D obtained from essential oils of plants of the genus Solidaco, such as Kometsuga, Tubera, and Solidago vulgare, and ylang-ylang oil [Tetrahedron Letters,
No. 27, p. 2263 (1969)], but the former method has drawbacks such as very low cyclopentane (less than 3%), and the latter method also requires complicated isolation and purification methods for germacrene D. However, since these methods require complicated steps and the yield of germacrene D is quite low, there are problems such as a significant decrease in the total yield, and these methods are difficult to employ in practice.

In view of this, the present inventors first directly irradiated light on the essential oil of a plant of the genus Solidaco, such as Lovatica or ylang-ylang oil, to produce β-bourbonene in extremely high yield with a simple operation. We have proposed a method (Japanese Patent Application No. 51-68554, 1982-9505), and when carrying out this method, acetone, especially aromatic ketones such as acetophenone, benzophenone, and xanthone, are added as a sensitizer. It was pointed out that this method is favorable in terms of the yield of β-bourbonene, and that the reaction rate (amount of conversion from germacrene D to β-bourbonene per unit irradiation time) is also increased, making it possible to significantly shorten the photoirradiation time. .

However, many of these aromatic ketones have low solubility in solvents, and especially when these aromatic ketones are added, a trace amount remains in β-bourbonene, so that the resulting β-bourbonene is not included in the fragrance composition. If mixed with other ingredients, it may have an unfavorable effect on the overall flavor.

This is a big problem, especially in the current situation where natural scents are preferred and it is therefore required to prepare flavors that are as natural as possible. For this reason, if it is necessary to remove the influence of such a trace amount of aromatic ketone remaining, it is troublesome to further purify β-bourbonene by column chromatography or the like. In order to solve these problems, the inventors conducted further research and found that
When producing β-bourbonene by irradiating essential oil containing germacrene D with light, using terpene ketones such as carvone, hyperitone, pulegone, verbenone, menthone, and piperitenone as a stimulant will reduce the yield of β-bourbonene and The degree of shortening of the reaction time (light irradiation time) is at least the same as when aromatic ketones are used, and it can be effectively used as a sensitizer, and the obtained β-bourbonene can be used in fragrance compositions. Even when added to the fragrance composition, there is no unfavorable effect on the flavor; rather, a synergistic effect between β-bourbonene and these terpene ketones occurs, creating a flavor composition with a more natural flavor. It is possible to formulate synthetic fragrance compositions such as synthetic peppers that impart flavor, can be widely incorporated into various fragrance compositions in relatively large quantities, and have an excellent flavor close to that of natural fragrances. The present inventors have discovered that there is no need to perform the troublesome operation of further purifying the obtained β-bulhonen by column chromatography or the like, leading to the present invention.

That is, the present invention provides essential oils containing germacrene D! The present invention provides a method for producing β-bourbonene, which comprises adding terpene ketones as a sensitizer to the essential oil when producing β-bourbonene by irradiation.

The present invention will be explained in detail below.

As the raw material essential oil used in the present invention, any essential oil containing germacrene D can be used, but those that are relatively easy to obtain and have a high content of germacrene D, such as solids It is preferable to use essential oils of plants of the genus Solidaco, such as Physcomitrella vulgaris, and Physcomitrella sinensis, essential oils of plants of the genus Cananga, such as Cananga odorata, ylang-ylang oil, cananga oil, or essential oils of plants of the genus Calum, such as Prunus japonicum.

In this case, the essential oil containing germacrene D can be used as it is, but if necessary, petroleum ether, petroleum benzine, n-hexane, cyclohexane, ether, benzene, toluene, ethyl acetate, methylene chloride, chloride, etc. ethylene, methanol, ethanol, acetone,
It can also be used after being diluted with one or a mixed solvent of two or more nonpolar or polar solvents such as acetonitrile and water.

In addition, when separating essential oils from the above-mentioned plants, appropriate methods such as steam distillation and solvent extraction are adopted, but when the solvent extraction is adopted, the solvent is not distilled off and the oil is left in the solvent. There is no problem in using dissolved essential oils as raw materials. Note that the essential oil can be subjected to pretreatment such as removing low-boiling components by fractional distillation or column chromatography before irradiation with light.

Therefore, in the present invention, one or two of terpene ketones such as carvone, piperitone, pulegone, verbenone, menthone, and piperitenone are added to the essential oil as a sensitizer.
Mix more than one seed.

In this case, the blending amount is usually 0.1 to 0.1 to the essential oil.
It is 100%. In the present invention, terpene ketones are added to the essential oil, and if necessary, the solvent is added to the reaction system, and the reaction system is irradiated with light to produce β-bourbonene.The light source for the light irradiation is a low-pressure mercury lamp or a high-pressure mercury lamp. Either method may be used, and either internal irradiation or external irradiation can be employed as the irradiation method.

In this case, when a low-pressure mercury lamp is used as a light source, petroleum ether, hexane, acetone, methanol, and ethanol are preferably used among the solvents, and when a high-pressure mercury lamp is used, methanol, ethanol, acetone, Preference is given to using toluene.
In addition, the time of light irradiation is 112 when no sensitizer is used.
0 to 1125, and by adding the above-mentioned terpene ketones as a sensitizer, the reaction is completed in such a short time and the irradiation time is significantly shortened. The essential oil after irradiation with light has β-bulponene as its main component and contains monoterpenes and sesquiterpenes, and can be used as a fragrance material or the like as it is or with the monoterpenes separated. When it is necessary to isolate β-bourbonene, it can be isolated by fractional distillation under reduced pressure, and can be isolated by such a simple operation. In this case, the β-bourbonene obtained by this fractional distillation still contains a trace amount of the terpene ketones added as a sensitizer, but the β-bourbonene containing the terpene ketones is different from the terpene ketones. Due to the synergistic action of β-bourbonene, when it is incorporated into synthetic spearmint bases and other fragrance compositions, terpenes give a more natural appearance and impart a good flavor to the fragrance composition. Ketones do not need to be removed from β-bourbonene and therefore β-
Bourbonene can be isolated and purified from the essential oil after the light irradiation by a simple operation such as fractional distillation, and there is no need to perform further purification operations such as column chromatography. In addition,
The yield of β-bourbonene obtained by fractional distillation under reduced pressure (the conversion rate of germacrene D contained in the essential oil to β-bourbonene) is around 90% or more, and the addition of terpene ketones, etc. As described above, β-bourbonene can be produced with a high conversion rate.

The obtained β-bourbonene is particularly effective as a fragrance material, and when incorporated into fragrance compositions, especially mint-based synthetic fragrance compositions, it imparts a natural feel and emphasizes the refreshing and refreshing feeling characteristic of mint-based fragrances. .

In addition, β-bourbonene can be prepared using known techniques (for example, J.A.
m. Chem. SOc. , vol. 9O, p. 6171 (196
Based on 8)), it can also be converted to α-bourbonene and used. As explained above, according to the present invention,
When essential oil containing germacrene D is irradiated with light, by adding terpene ketones as a stimulant, it can be efficiently achieved in a short time of 1120 to 1125 compared to the case without addition, and at a high conversion rate of around 90% or more. β-Bourbonene can be produced with good yield.

In addition, β-bourbonene can be separated and purified by simple operations such as fractional distillation under reduced pressure from the essential oil after irradiation with light, and terpene ketones can be separated by further complicated purification operations such as column chromatography. There is no need to do so, and the yield of β-bourbonene can be increased. Furthermore, the obtained β-
Due to its synergistic effect with terpene ketones, bourbonene is widely incorporated into various fragrance compositions to impart a more natural-like flavor and a good flavor.

For example, when β-bourbonene is added to a synthetic spearmint base, the flavor comes closer to that of natural spearmint oil, further enhancing the unique flavor of spearmint and emphasizing its naturalness. Therefore, conventionally, toothpastes, mouth fresheners,
It is suitable for blending with mint flavors such as spearmint and peppermint, which are popular as flavors for chewing gum, etc., and better matches the preference for natural scents. In addition, β-bourbonene obtained according to the present invention can impart better flavor due to its synergistic effect with terpene ketones, so the amount of β-bourbonene to be blended in flavor compositions can be increased. It can give better flavor. EXAMPLES The present invention will be explained in more detail below with reference to Examples and Usage Examples.

[Example 1] The leaf part 60k9 of Versatica albatross was steam-distilled to obtain essential oil 120y.

To 100.0 y of this essential oil (containing 43.5 y of germacrene D) were added 1 f of ethanol and 1 g of pulegone as a sensitizer, and internally irradiated with light from a high-pressure mercury lamp until germacrene D almost disappeared (11 terama). After the reaction was completed, vacuum fractional distillation was performed to obtain 39.7y of β-bourbonene. The conversion rate was 91.3%. Note that the conversion rate was calculated using the following formula.

(The same applies hereinafter) [Example 2], ylang-ylang oil 100.0y (germacrene D23.
100 ml of methylene chloride and 1.0 y of Caliphon as a sensitizer were added to the mixture (containing 4y), and the interior was irradiated with light from a high-pressure mercury lamp until germacrene D was almost completely disappeared (10!L Terama).

After completion of the reaction, vacuum fractional distillation is performed to obtain β-bulponene 22.
2q (conversion rate 94.9%) was obtained. [Example 3] N-hexane 1e and 0.1f of piperitone as a sensitizer were added to 100.0 g of cananga oil (containing germacrene DlO.Oy), and the light of a low-pressure mercury lamp was applied until germacrene D almost disappeared (5 hours). ) Internally irradiated. After the reaction, vacuum fractional distillation was performed to obtain β-bourbonene 8.8y (conversion rate 88.0
%) was obtained. [Example 4] Hymeuikiyo leaf part 20k9
was steam distilled to obtain essential oil 23y.

To 10.0 y of this essential oil (containing 8 y of germacrene D) were added 200 ml of benzene and 1 y of pulegone as a sensitizer, and externally irradiated with light from a high-pressure mercury lamp until germacrene D almost disappeared (3 hours). After the reaction was completed, vacuum fractional distillation was performed to obtain β-bourbonene 7.2y (conversion rate 90.0%). [Example 5] 1 e of toluene and 1 v of carvone as a sensitizer were added to 100.0 y of ylang-ylang oil (containing 23.4 y of germacrene D), and the light of a high-pressure mercury lamp was internally irradiated until germacrene D almost disappeared (for one exclamation period). did.

After the reaction is completed, vacuum fractional distillation is performed to obtain β-bourbonene 22.
7y (conversion rate 97.0%) was obtained. [Example of use] 1.0 y of acetophenone and 1 e of toluene were added to the β-bourbonene obtained in Example 5 and 100.0 y of ylang-ylang oil (containing 23.4 da of germacrene D), and a high... After internal irradiation with pressure mercury lamp light until germacrene D almost disappeared (■ hours), β-bourbonene was obtained by fractional distillation under reduced pressure (19.3y of β-bourbonene was obtained by this method, and its conversion The rate was 82.5%.

) and 1. respectively on a synthetic spearmint base. These synthetic fragrances were compared with natural spearmint oil (control) in a sensory test conducted by a panel of six experts. Table 1 shows the results. (7) Evaluation criteria 0: No difference from the control 1: Slightly inferior to the control 2: Inferior to the control From the above results, when carvone (terpene-based cyclic ketone) is used as a sensitizer, acetophenone (aromatic ketone) The conversion rate from germacrene D to β-bourbonene is higher than when carvone is used, and the reaction rate (the amount of conversion from germacrene D to β-bourbonene per unit irradiation time) is the same or higher. β obtained by
- It has been found that bourbonen, when incorporated into a fragrance composition, imparts a more natural appearance and provides a better aroma.

Claims (1)

[Scope of Claims] 1. A method for producing β-bourbonene, which comprises adding terpene ketones as a sensitizer to the essential oil when producing β-bourbonene by irradiating an essential oil containing germacrene D with light. . 2. The method for producing β-bourbonene according to claim 1, wherein the terpene ketones are one or more selected from carvone, piperitone, pulegone, verbenone, tanthone, and piperitenone.