JPH064035B2 - Separation method of cyclopentenone derivatives - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention has the general formula (I) (Wherein, R ₁ represents a hydrogen atom or a methyl group, R ₂ is C ₁ ~ ₃ alkyl group, respectively alkenyl group or alkynyl group.) The optically active represented by a cyclopentenone alcohol of the general formula (II ) (In the formula, R represents a lower alkyl group, and R ₁ and R ₂ have the same meanings as described above.) A method for separating a mixture of optically active cyclopentenone esters represented by

The optically active cyclopentenone alcohols and cyclopentenone esters represented by the above general formulas (I) and (II) are compounds useful as intermediates for pharmaceuticals, agricultural chemicals, and fragrances, and some methods for their production are also available. Are known [Japanese Patent Publication No. 56-9917 and Japanese Patent Laid-Open No. 58-31994].
No. 58, JP-A-58-47495, Agr. Biol. Che
m., 39 (1), 89-96 (1975)], typically the general formula (III) (In the formula, R, R ₁ and R ₂ have the same meanings as described above.) A cyclopentenone ester represented by: is used as a raw material, and one of the optically active substances in the cyclopentenone is hydrolyzed (asymmetrically). Hydrolysis).

However, in the above-mentioned hydrolysis method, the optically active cyclopentenone alcohols and cyclopentenone esters represented by the general formulas (I) and (II) are obtained as a mixture. It is necessary to separate them, and as a method therefor, the reaction solution obtained by hydrolysis is subjected to extraction treatment with a solvent such as ethyl acetate and ethyl ether to transfer both to an organic layer, and chromatography is used from this organic layer. The method of separating both was adopted.

However, this method has problems such as complicated processing operations and is not always satisfactory as an industrial method.As a result of further study to develop an industrially advantageous separation method, the present invention was completed. I arrived.

That is, the present invention is the asymmetric hydrolysis of the cyclopentenone ester represented by the general formula (III), the obtained optically active cyclopentenone alcohol represented by the general formula (I) and the general formula (II ), An aqueous solution containing a mixture of the optically active cyclopentenone ester is subjected to extraction treatment with an aliphatic or aromatic hydrocarbon, and the optically active cyclopentenone ester is separated from the separated organic layer from the aqueous layer. A method for separating cyclopentenones, which is characterized in that optically active cyclopentenone alcohols are obtained.

The asymmetric hydrolysis of the cyclopentenone ester represented by the general formula (III) is usually performed using an enzyme or a microorganism having the ability to hydrolyze any one of the optically active forms of the cyclopentenone ester, For example, when the hydrolysis is carried out using an enzyme or a microorganism having the ability to hydrolyze the d-form of the starting cyclopentenone ester, the compound of the general formula
The d-cyclopentenone alcohol represented by (I) is obtained, and the 1-form represented by the general formula (II), which is another optically active substance in the raw material, remains as an unreacted product. A mixture of -cyclopentenone alcohol and l-cyclopentenone ester is obtained, while
When the hydrolysis is performed using an enzyme or a microorganism that has the ability to hydrolyze the 1-form of the starting cyclopentenone esters, contrary to the above, 1-cyclopentenone alcohol and d-cyclopentenone A mixture of esters is obtained.

Examples of enzymes or microorganisms used in the hydrolysis reaction include animal hydrolases such as pig liver esterase, beef liver esterase, pig pancreatic esterase, dog liver esterase, pig phosphatase, barley, and β-amylase obtained from potato. , Plant hydrolases such as lipase obtained from wheat (manufactured by Sigma, Wheat Germ),
Rhodotorual, Trichoderma, Candida, Hansenula
Genus, Bacillus, Achromobacter, Nocardia, Chrom
Genus obacterium, Genus Flavobacterium, Genus Rizopus, Mucor
Genus, Aspergillus, Alkaligenes, Torulopsis, Co
rynebacterium, Endomyces, Saccaromyces, Arth
robacter, Metshnikowia, Pleurotus, Streptmyc
es, Proteus, Gliocladium, Acetobacter, Hel
genus minthosporium, genus Brevibacterium, genus Escherichia,
Citrobacter, Absidia, Micrococcus, Pediococc
Examples thereof include microorganisms belonging to each genus such as genus us, genus Klebsiella, genus Geotrichun, genus Pseudomonas, lichens, algae, etc., and microorganisms or hydrolytic enzymes obtained from them.

In the hydrolysis reaction, the raw material cyclopentenone ester and the above enzyme or microorganism are usually treated with a water-soluble organic solvent (for example, methanol, ethanol, tetrahydrofuran,
Dioxane, acetone, etc.) is stirred in a buffered aqueous solution which may contain 0 to 30% by weight.

As the buffer solution, a commonly used buffer solution of an inorganic acid salt such as sodium phosphate and potassium phosphate, a buffer solution of an organic acid salt such as sodium citrate, and the like are used.
Is in the range of 4 to 10, preferably 5 to 9, and the concentration is usually in the range of 0.05 to 2M, preferably 0.05 to 0.5M.

The reaction temperature is usually 20 to 40 ° C., and the reaction time is generally 10 to 70 hours, but it is not limited thereto.

By such hydrolysis, an aqueous solution containing a mixture of the optically active cyclopentenone alcohol and cyclopentenone ester represented by the general formulas (I) and (II) is obtained, and the aqueous solution is subjected to extraction treatment to separate the two. be able to.

Aliphatic or aromatic hydrocarbons are used as the extraction solvent, and specific examples include pentane, hexane, heptane, octane, decane, cyclopentane, cyclohexane, benzene, toluene, xylene, etc. It is used as a mixture of the above.

The amount of the extraction solvent used is not particularly limited, but is usually 0.3 to 100 times by weight, preferably 0.3 to 3 times the optically active cyclopentenone ester represented by the general formula (II) in the aqueous solution.
It is 0 times the weight.

The extraction temperature is usually in the range of 0 ° C. or higher and the boiling point of the extraction system or lower.

As the extraction method, various conventionally known methods are applied and are not particularly limited.

By such an extraction treatment, the optically active cyclopentenone ester is transferred to the organic layer, separated from the aqueous layer, and then the solvent is removed from the organic layer, whereby the optically active cyclopentenone ester can be isolated.

On the other hand, after separating the organic layer, the aqueous layer is concentrated and further distilled, or if necessary, salts such as sodium chloride and sodium sulfate are added to the aqueous layer or the concentrated aqueous layer for salting out, followed by methylation. Isobutyl ketone, ethyl acetate,
The optically active cyclopentenone alcohol can be isolated by a method such as extraction treatment using a solvent having a high extraction effect such as n-butanol and removing the solvent from the obtained organic layer.

Thus, according to the method of the present invention, an optically active cyclopentenone ester and an optically active cyclopentenone alcohol are industrially produced from an asymmetric hydrolysis reaction liquid of cyclopentenone ester, for example, by the action of an enzyme or a microorganism. It can be advantageously separated by easy means.

Hereinafter, the present invention will be described with reference to examples.

Example 1 dl-4-acetoxy-3-methyl-2-propargyl-
2-Cyclopentenone 2g, Porcine Liver Esterase
80 mg (manufactured by Sigma), 80 ml of 0.1M aqueous solution of phosphoric acid buffer (PH6) and 5 ml of methanol were mixed to obtain 30
Stir vigorously at 0 ° C. for 20 hours.

After completion of the reaction, the reaction solution is centrifuged to obtain a supernatant. The supernatant is extracted twice with 15 ml of toluene-hexane (mixing ratio 1/1). The extracted oil layers were combined and concentrated to obtain 1.02 g of an oily substance having a content of d-4-acetoxy-3-methyl-2-propargyl-2-cyclopentenone of 97%. α] ²⁰ _D +3
4.9 ° (c = 1, chloroform). The incorporation of l-4-hydroxy-3-methyl-2-propargyl-2-cyclopentenone was 0.9%.

On the other hand, the aqueous layer was concentrated to 1/2 volume under reduced pressure, and then salt 20 was added.
g, and extracted 4 times with 20 ml of methyl isobutyl ketone. Concentrate the methyl isobutyl ketone layer to l-
4-hydroxy-3-methyl-2-propargyl-2-
0.76 g of an oil with a cyclopentenone content of 96% was obtained.
α] ²⁰ _D −15.7 ° (c = 1, chloroform). d-4-
The acetoxy-3-methyl-2-propargyl-2-cyclopentenone contamination was 0.2%.

Example 2 3 g of dl-4-acetoxy-2-allyl-2-cyclopentenone, 400 mg of REVERSE PL (manufactured by Meito Co.) and 0.1
Mix 150 ml of M phosphate buffer aqueous solution (pH 7) and stir vigorously at 20 to 25 ° C. for 20 hours.

After the reaction was completed, the reaction solution was mixed with toluene-hexane (mixing ratio 1 /
2) Extract twice with 45 ml. The organic layer was dried over magnesium sulfate and then concentrated to give 1.90 g of an oily substance containing 98.1% of l-4-acetoxy-2-allyl-2-cyclopentenone.
To get α] ²⁰ _D −65.8 ° (c = 1, chloroform).
The admixture of d-2-allyl-4-hydroxy-2-cyclopentenone was 0.1%.

On the other hand, 50% salt is added to the aqueous layer after extraction with toluene-hexane.
g, and extracted 5 times with 40 ml of methyl isobutyl ketone. Combine the methyl isobutyl ketone layers, dry over magnesium sulfate, and concentrate to d-2-allyl-
4-hydroxy-2-cyclopentenone content 96.5%
0.79 g of oil is obtained. α] ²⁰ _D + 19.3 ° (c = 1, chloroform).

The contamination with l-3-acetoxy-2-allyl-4-cyclopentenone was 0.15%.

Example 3 5 g of dl-4-acetoxy-2-allyl-3-methyl-2-cyclopentenone, 300 mg of Porcine Liver Esterase (manufactured by Sigma), 0.1 M phosphate buffer aqueous solution (pH
7) Mix 90 ml and 10 ml of methanol, and mix 25 to 3
Stir at 0 ° C. for 24 hours.

After completion of the reaction, the reaction solution is centrifuged to obtain a supernatant. The supernatant is extracted twice with 30 ml of hexane. The organic layer was dried over magnesium sulfate and then concentrated to obtain 2.62 g of an oily substance containing 97.5% content of d-4-acetoxy-2-allyl-3-methyl-2-cyclopentenone. α] ²⁰ _D + 27.8 ° (c = 1, chloroform) 1-2% allyl-4-hydroxy-3-methyl-2-cyclopentenone mixed in 0.2%
Met.

On the other hand, 50 g of salt was added to the aqueous layer after extraction with hexane,
Extraction is carried out 4 times with 50 ml of methyl isobutyl ketone.
The methyl isobutyl ketone layers were combined, dried over magnesium sulfate, and then concentrated to obtain 1.85 g of an oily substance having a 96% content of 1-2-allyl-4-hydroxy-3-methyl-2-cyclopentenone. α] ²⁰ _D −13.2 ° (c = 1, chloroform). The contamination with l-4-acetoxy-2-allyl-3-methyl-2-cyclopentenone was 0.2%.

Example 4 2 g of dl-4-acetoxy-2,3-dimethyl-2-cyclopentenone, Lipase M-AP (manufactured by Amano Pharmaceutical Co., Ltd.) 10
0 mg and 0.1 M phosphate buffer aqueous solution (pH 7) 1
00 ml is mixed and stirred at 25-30 ° C for 24 hours.

After completion of the reaction, the reaction solution is centrifuged to obtain a supernatant. The supernatant was mixed with 20 ml of hexane-toluene (mixing ratio 1/1) to 2
Extract twice. The organic layer was dried over magnesium sulfate and then concentrated to obtain 1.21 g of an oily substance containing d-4-acetoxy-2,3-dimethyl-2-cyclopentenone (content 96.5%). α] ²⁰ _D + 34.2 ° (c = 1, chloroform). l-
The contamination of 4-hydroxy-2,3-dimethyl-2-cyclopentenone was 0.3%.

On the other hand, 30 g of sodium chloride was added to the separated aqueous layer, and extraction was performed 4 times with 40 ml of ethyl acetate. The ethyl acetate layers were combined, dried over magnesium sulfate, and concentrated to l
0.52 g of an oily matter containing 97% of 4-hydroxy-2,3-dimethyl-2-cyclopentenone was obtained. α] ²⁰ _D
-20.2 ° (c = 1, chloroform) l-4-acetoxy-2,3-dimethyl-2-cyclopentenone was not mixed.
It was 15%.

Claims (1)

[Claims] 1. A general formula (Wherein the R is a lower alkyl group, R ₁ represents a hydrogen atom or a methyl group, an alkyl group of R ₂ is C ₁ ~ _3, respectively an alkenyl group or alkynyl group.) The cyclopentenone ester represented by General formula obtained by asymmetric hydrolysis (In the formula, R ₁ and R ₂ have the same meanings as described above.) And an optically active cyclopentenone alcohol represented by the general formula (In the formula, R, R ₁ and R ₂ have the same meanings as described above.) An aqueous solution containing a mixture of the optically active cyclopentenone ester represented by the following formula is subjected to extraction treatment with an aliphatic or aromatic hydrocarbon. , A method for separating a cyclopentenone derivative, which comprises obtaining an optically active cyclopentenone ester from the separated organic layer and an optically active cyclopentenone alcohol from the aqueous layer, respectively.