JPH0537140B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to general formulas [] and [′]

【formula】

The present invention relates to a method for producing a mixture of cyclopentyl acetic acids represented by the following formula: (wherein R represents an alkyl group, an alkenyl group, or an alkynyl group, and R' represents an alkyl group.) In the above general formula [] compound, for example, R
The compound in which is n-pentyl group and R′ is methyl group is called methyl dihydrodiasmonate,
It is well known as a luxury fragrance. It is also well known that compounds of the general formula ['] having the same substituents have effects such as fragrance and growth inhibition effects on plants. However, although nothing has been known about these compounds, much less the use of the mixture, the present inventors believe that each of these compounds can be used alone when used as a fragrance. It has been found that the use of a mixture as a fragrance is superior in terms of spreadability and lingering fragrance as a fragrance, and is therefore extremely useful. By the way, methods for producing compounds of general formula ['] and ['] are known, for example, the following methods are known for compounds of general formula ['], but methods for producing compounds of general formula ['] and [']
There is no known method for producing mixtures of these, therefore, in order to obtain these mixtures, each compound must be synthesized separately and then the two must be mixed. However, this method requires different starting materials, reagents, reaction means, etc., making the production process extremely complicated, and is by no means satisfactory for industrial production. a Agric.Biol.Chem., 44(12), 2857-2864
(1980) b Synthetic Communications, 4(6), 335
~339 (1974) For this reason, the present inventors prepared a mixture of only the starting materials, and hereinafter, using the same reaction operations and the same reagents, the present inventors conducted an investigation to industrially advantageously produce a mixture of the compounds of general formulas [] and [']. As a result,
This led to the present invention. That is, the present invention relates to general formulas [] and [′]

【formula】

[Formula] (In the formula, R represents an alkyl group, an alkenyl group, or an alkynyl group.) 2-substituted-2-cyclopentenone and 2
A cyclopentenone mixture consisting of -substituted-4-cyclopentenone is given the general formula [] CH ₂ (COOR') ₂ [] (wherein R' represents an alkyl group) in the presence of a basic catalyst. General formulas [] and [′] can be obtained by adding the malonic acid ester shown. (In the formula, R and R' have the same meanings as above.) The above general formulas [] and ['] are characterized in that a mixture of cyclopentanone derivatives represented by the formula is obtained and then heat treated with water. The present invention provides a method for producing a mixture of cyclopentyl acetic acids represented by: The mixture of cyclopentenone compounds represented by the general formulas [] and ['] used as raw materials in the present invention may be prepared by mixing the respective compounds prepared in advance, but, for example, by the method shown below, Advantageous is a method of producing a mixture of both from one raw material compound. The mixing ratio of the compound of general formula [] and the compound of general formula [′] is not particularly limited, and a mixture of any ratio can be used as a raw material compound in the present invention,
When a mixture of compounds of general formulas [] and ['], which are the object compounds of the present invention, is used as a fragrance, the mixing ratio of the raw material compounds is []:
[']=70-95:5-30 is preferred. Examples of such a mixture of cyclopentenone compounds include the following compounds. 2-methyl-2-cyclopentenone and 2-
Mixture of methyl-4-cyclopentenone, 2-ethyl-2(and 4)-cyclopentenone, 2-n
-propyl-2(and 4)-cyclopentenone,
2-isopropyl-2(and 4)-cyclopentenone, 2-n-butyl-2(and 4)-cyclopentenone, 2-isobutyl-2(and 4)-cyclopentenone, 2-n-pentyl- 2 (and 4)
-cyclopentenone, 2-isopentyl-2(and 4)-cyclopentenone, 2-n-hexyl-2(and 4)-cyclopentenone, 2-n-heptyl-2(and 4)-cyclopentenone , 2-
Allyl-2(and 4)-cyclopentenone, 2-
(w-butenyl)-2(and 4)-cyclopentenone, 2-(2-butynyl)-2(and 4)-cyclopentenone, 2-(2-cis-pentenyl)-2
(and 4)-cyclopentenone, 2-(2-trans-pentenyl)-2(and 4)-cyclopentenone, 2-(2-cis-hexenyl)-2(and 4)-cyclopentenone, 2 -(3-cis-hexenyl)-2(and 4)-cyclopentenone, 2
-(α-methylallyl)-2(and 4)-cyclopentenone, 2-propargyl-2(and 4)-cyclopentenone, 2-(2-pentynyl)-2(and 4)-cyclopentenone. Such a cyclopentenone mixture and the general formula []
The addition reaction of malonic acid ester shown in is carried out in the presence of a basic catalyst. Examples of malonic acid esters used in this reaction include dimethyl malonate, diethyl malonate, di-n-propyl malonate, diisopropyl malonate, di-n-butyl malonate, and di-n-pentyl malonate. Examples include di-lower alkyl esters of acids, and the amount used is at least 1 mole based on the mixture, preferably 1.2 to 3 moles.
It is twice the mole. Examples of basic catalysts include sodium methylate, sodium ethylate, potassium t-
Examples include metal alcoholates such as butyrate, metal hydrides such as sodium hydride, lithium hydride, and potassium hydride, metals such as sodium, potassium, and lithium, and strong basic amines such as DBU, with metal alcoholates being particularly preferred. used. Incidentally, when a metal is used as a catalyst, alcohols are used as a solvent. The amount of the catalyst used is usually 0.01 to 3 times the mole, preferably 0.03 to 1.5 times the mole of the cyclopentenone mixture as a raw material. Reaction temperature is -50~80℃, preferably -40~60℃
is within the range of Examples of reaction methods include adding a basic catalyst to a cyclopentenone mixture and then adding a malonic ester, adding a basic catalyst to a mixture of a cyclopentenone mixture and a malonic ester, and adding a basic catalyst to a cyclopentenone mixture and a malonic ester. This can be carried out by any method, such as adding a cyclopentenone mixture to a catalyst mixture, and is not particularly limited. However, in order to obtain a mixture of compounds of general formulas [] and ['] without using a solvent or with the least amount of solvent used and with a good yield, it is necessary to add basicity to the mixture of cyclopentenone mixture and malonic acid ester. The method of adding a catalyst is preferred. When this method is used, there is no precipitation of crystals during cooling, and handling is extremely easy. This reaction does not necessarily require a solvent and can be carried out without a solvent. When using a solvent, it can be used without any particular restriction as long as it is insoluble in the reaction, such as alcohols such as methanol, ethanol, isopropyl alcohol, tetrahydrofuran, dioxane, and toluene, ethers, or aromatic hydrocarbons alone. or a mixture. When a solvent is used, the amount used is not particularly limited, but is generally 0.2 to 20 times the weight of the cyclopentenone mixture. There is no particular restriction on the reaction time. In this way, a mixture of cyclopentanone derivatives represented by the general formulas [] and ['] can be obtained easily and in good yield, and these can be separated from the reaction solution by conventional separation means such as extraction, separation, concentration, distillation, etc. However, the reaction mixture can be used in the next step without any particular separation. The desired general formulas [] and [′] are obtained from the mixture of cyclopentanone derivatives thus obtained.
In order to obtain a mixture of cyclopentyl acetic acids represented by , a mixture of cyclopentanone derivatives is heated with water. The amount of water used in this reaction is required to be at least equimolar to the mixture of cyclopentanone derivatives, preferably in the range of 1 to 20 times the molar amount. Although it is not necessary to use a solvent in this reaction, it is preferable to use a solvent. Examples of such solvents include alcohols such as methanol, ethanol, isopropyl alcohol, and butanol, ethers such as tetrahydrofuran and dioxane, and dimethyl Sulfoxide, sulfones such as sulfolane, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, N,N'-dimethylimidazolidone,
Examples include amides such as hexamethyltriamide phosphate, and generally water-soluble solvents are preferred. In addition, when alcohol is used as a solvent in this reaction, the type of alcohol is one that has the same alkyl group as that forming the ester of the cyclopentanone derivative represented by the general formulas [] and ['], which are the raw materials. Alcohol is preferable, and if alcohols having different alkyl groups are used, a transesterification reaction may occur and an ester different from the cyclopentanone derivative used as a raw material may be produced. The amount of such a solvent used is usually 1 to 50 times the weight of the cyclopentanone derivative. Reaction temperature is 90-300℃, preferably 100-240℃
It is. There is no particular restriction on the reaction time. In this reaction, a catalyst may be used to improve the reaction rate or yield, and such catalysts include, for example, sodium chloride, sodium bromide, potassium chloride, potassium bromide, lithium chloride, lithium iodide, and iodine. Examples include metal halides such as sodium chloride and potassium iodide, and metal cyanides such as sodium cyanide and potassium cyanide. When a catalyst is used, the amount used is usually 0.1 to 3 times the mole of the cyclopentanone derivative. This reaction is usually carried out at normal pressure, but it can also be carried out under increased pressure. Examples of the reaction method include heating a mixture of a cyclopentanone derivative, water and a solvent mixed in advance, or heating water or a mixture of water and a solvent in a mixed solution of a cyclopentanone derivative or a solvent. Any method may be employed, such as a method of supplying a cyclopentanone derivative, a method of heating a mixture of a cyclopentanone derivative, water, and a solvent in a short time through a pipe reactor or the like. Through such a reaction, the desired general formula []
Cyclopentyl acetic acids represented by . The present invention will be explained below with reference to Examples. Example 1 2-n-pentyl-2-cyclopentenone [-
1] and 2-n-pentyl-4-cyclopentenone ['-1] ([-1]/['-
1] = 90/10) 15.2g, malonic acid dimethyl ester 18.5g and methanol 2ml, -10~
14 of sodium methylate while cooling to −20 °C.
% methanol solution was added dropwise over 1 hour. After finishing dropping, keep warm at the same temperature for 3 hours. After the reaction is complete, add 0.45g of acetic acid, then add hexane.
Add 50ml and 20ml water. After separation, the organic layer was washed with 20 ml of water, and hexane and dimethyl malonate were distilled off under reduced pressure to form dimethyl-2-n-pentyl-3-oxo-cyclopentyl malonate [-1] and dimethyl-3. -n
- Concentrated residue containing 27.82 g of a mixture of pentyl-4-oxocyclopentyl malonate ['-1]
Obtained 29.60g. The entire amount of this residue is charged into a reaction device equipped with a distillation device,
While heating to 200-210℃ and stirring, add 15 ml of water-methanol mixture (water/methanol = 1/2 volume ratio) to 3
It takes time to feed the reaction liquid below the surface. Unreacted water and by-product methanol are continuously distilled off. After completion of the reaction, the reaction solution was distilled under reduced pressure to obtain 2-n-pentyl-3-oxo-cyclopentyl acetic acid methyl ester [-1] and 3-n-pentyl-4.
-Mixture of oxo-cyclopentyl acetic acid methyl ester ['-1] ([-1]/[['-1]=
91/9] 21.25 g was obtained. bp 113-119℃/0.1-0.3mmHg Example 2 In a flask similar to that used in Example 1, 2-allyl-2-cyclopentenone [-2] and 2-
Mixture of allyl-4-cyclopentenone ['-2] ([-2]/['-2] = 80/20) 12.22
g, 19.1 g of malonic acid dimethyl ester and 3 ml of methanol were added, and while cooling to -10 to -15°C, a 28% methanol solution of sodium methylate was prepared.
1.3g was added dropwise over 1 hour. After finishing dropping,
Keep warm at the same temperature for 3 hours. After the reaction is complete, add 0.45g of acetic acid, then add hexane.
Add 40ml and 20ml water. Thereafter, 24.90 g of a mixture of dimethyl-allyl-3-oxo-cyclopentyl malonate [-2] and dimethyl-3-allyl-4-oxo-cyclopentyl malonate ['-2] was treated in the same manner as in Example 1. 26.48 g of concentrated residue was obtained. The entire amount of this concentrated residue was charged into a reaction device equipped with a distillation device, and 12 ml of water-methanol mixture (water/methanol = 1/2 volume ratio) was heated to 200-215°C with stirring.
was fed below the surface of the reaction liquid over a period of 4 hours. Unreacted water and by-product methanol are continuously distilled off. After the reaction, the reaction solution was distilled under reduced pressure to obtain a mixture of 2-allyl-3-oxo-cyclopentyl acetic acid methyl ester [-2] and 3-allyl-4-oxo-cyclopentyl acetate methyl ester ['-2] ([- 2]/[['-2]=78/22]
18.23g was obtained. bp 99-102℃/0.3-0.5mmHg Example 3 Into a flask similar to that used in Example 1, add 2-2'-
cis-pentenyl-2-cyclopentenone [-
3] and 2-2'-cis-pentenyl-4-cyclopentenone ['-3] ([-3]/
['-3] = 85/15), 37.2 g of malonic acid dimethyl ester, and 4 ml of methanol, -
While cooling to 10 to -20°C, 5.2 g of a 14% methanol solution of sodium methylate is added dropwise over 1 hour. After finishing dropping, keep warm at the same temperature for 4 hours. After the reaction is complete, add 0.9g of acetic acid, then add hexane.
Add 60ml and 30ml water. The following treatment was carried out in the same manner as in Example 1, and the concentrated residue was dimethyl-2-2'-cis-pentenyl-3-oxo-cyclopentyl malonate [-3] and dimethyl-3-2'-cis-pentenyl-4- 57.18 g of extract containing 53.74 g of a mixture of oxo-cyclopentyl malonate ['-3] was obtained. 51.46 g of this extract was charged into a reaction device equipped with a distillation device, and heated to 205 to 215°C while stirring to create a water-methanol mixed solution (water/methanol = 1/3 volume ratio).
35 ml was supplied below the surface of the reaction solution over a period of 3 hours. Unreacted water and methanol are continuously distilled off. After completion of the reaction, the reaction solution was distilled under reduced pressure to obtain 2-2'-cis-pentenyl-3-oxo-cyclopentyl acetic acid methyl ester [-3] and 3-2'-cis-pentenyl-4-oxo-cyclopentyl acetate [-3]. '-3] mixture ([-3]/
[['-3] = 84/16] 35.64 g was obtained. bp 115-123℃/0.1-0.3mmHg Example 4 Into the same flask as used in Example 1, 2-n-
A mixture of pentyl-2-cyclopentenone [-1] and 2-n-pentyl-4-cyclopentenone ['-1] ([-1]/['-1]=
75/25) 30.4g and malonic acid dimethyl ester
37 g was charged, and 5.2 g of a 14% methanol solution of sodium methylate was added dropwise over 1 hour while cooling to -5 to -10°C. After finishing dropping, keep warm at the same temperature for 4 hours. After the reaction is complete, add 0.9 g of acetic acid, and further add 60 ml of hexane and 30 ml of water. Hereinafter, the same treatment as in Example 1 was carried out, and dimethyl-2
Concentrated residue 59.23 containing 55.08 g of a mixture of -n-pentyl-3-oxo-cyclopentyl malonate [-1] and dimethyl-3-n-pentyl-4-oxo-cyclopentyl malonate ['-1]
I got g. Add dimethylformamide to 53.31 g of this concentrated residue.
Add 150g and 7.5g of water, and stir at 130-140°C for 15 hours. After the reaction is complete, cool the reaction solution and add 30 mL of water.
ml and then extracted with hexane. After washing the extracted organic layer with water and drying with magnesium sulfate,
Concentrate and further distill under reduced pressure to obtain 2-n-pentyl-
3-oxo-cyclopentyl acetic acid methyl ester [-1] and 3-n-pentyl-4-oxo-cyclopentyl acetate methyl ester ['-1]
mixture ([-1]/[['-1]=77/23]
35.28g was obtained.

Claims (1)

[Claims] 1 2-substituted-2-cyclopentenone represented by the general formulas [Formula] and [Formula] (wherein R represents an alkyl group, an alkenyl group, or an alkynyl group) and 2
Malonic acid represented by the general formula CH ₂ (COOR') ₂ (wherein R' represents an alkyl group) is added to a cyclopentenone mixture consisting of -substituted-4-cyclopentenone in the presence of a basic catalyst. Addition of ester to obtain a mixture of cyclopentanone derivatives of the general formulas [Formula] and [Formula] (wherein R and R' have the same meanings as above), and then heat treatment with water. Process 2 for producing a mixture of cyclopentyl acetic acids represented by the general formulas [Formula] and [Formula] (wherein R and R' have the same meanings as above) 2-Substituted-2-cyclo The mixing ratio of pentenone and 2-substituted-4-cyclopentenone is 70 to 95:5.
30. The method of claim 1, wherein: