JPH03201996A - Production of optically active secondary alkyn alcohol by biochemical procedure - Google Patents

Abstract

PURPOSE:To obtain the title substance useful as a medicine, agricultural chemical and intermediate raw material thereof in high yield by reacting a specific (R,S)-ester with a specific alcohol in an organic solvent in the presence of an enzyme having ability capable of carrying out asymmetric alcoholysis. CONSTITUTION:An (R,S)-ester expressed of formula I ((l) is 0-4; (m) is 0 or 1; (n) is 0-4; C* is asymmetric carbon) is subjected to a reaction with an alcohol in organic solvent in the presence of an enzyme having ability (when an alcohol is present) capable of preferentially carrying out asymmetric alcoholysis with either one ester of R body or S body to carry out alcoholysis and resolved into an optically active alcohol rich in either one of R body or S body expressed by formula II to provide the objective compound.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing a specific optically active secondary alkyne alcohol by biochemical techniques.

[Conventional technology]

Optically active alcohols are in high demand and are known as promising compounds in the future, as biologically active substances and intermediate raw materials for medicines, agricultural chemicals, and the like, or as synthetic raw materials for liquid crystals.

However, the following general formula % formula %() (+2=O~4.m=0 or 1.C"=asymmetric carbon)
Alkyne alcohols with triple viscosity, as shown in
In many cases, unless it contains one or the other in high purity, it cannot be used as an intermediate for agricultural medicines that exhibit sufficient physiological activity. Also, if an optical isomer that does not exhibit the desired physiological activity is mixed in.

Causes serious side effects. For this reason, in order to obtain the optically active form of the alkyne alcohol represented by formula (II), it has conventionally been necessary to optically resolve the racemic form obtained by ordinary synthetic chemical methods or to perform asymmetric synthesis. Alternatively, methods have been adopted in which optically active raw materials such as sugars and amino acids are used as starting materials and are synthesized from the beginning, but these methods involve complicated steps.

It wasn't always an advantageous method.

[Problem to be solved by the invention]

An object of the present invention is to overcome the drawbacks of the prior art described above and to provide an industrially advantageous method for producing an optically active secondary alkyne alcohol represented by formula (II).

[Means to solve the problem]

Previously, the present invention has been carried out in an industrially advantageous manner.
) As a result of research to find a method for producing optically active alkyne alcohol derivatives shown in In this case, we have discovered that it is possible to efficiently separate an optically active ester and its enantiomer, an alcohol, and have completed the present invention.

That is, according to the present invention, the following formula (1) (m=0-
4. m=0 or 1, n=0-4, C*=m=carbon)
It has the ability to act on the (ops)-ester represented by n! to perform an asymmetric alcoholysis reaction with alcohol preferentially with either the 8- or 3-ester ester. In the presence of element 1, the (OSS)-ester represented by formula (1) above is reacted with alcohol in an organic solvent to perform an alcoholysis reaction, resulting in the following formula (
II) Provided is a method for producing an optically active secondary alkyne alcohol characterized by: 1 [1], which is divided into optically active alcohols enriched in either 8- or 3-isomers represented by:

The present invention is an enzymatic reaction in an organic solvent.

Because it is a reaction system with low moisture content, it does not cause hydrolysis reactions, keeps the enzyme stable in organic solvents, and is characterized by easy separation after 9 reactions and the possibility of reuse. In addition, since microbial contamination is unlikely to occur,
+,'! It also has the advantage that no special equipment or detergents are required.

In the present invention, (l(,S)-
Ester is a compound represented by the formula (+) in 1);

Specific examples of such (R,S)-esters include aliphatic carboxylic acids in which the acid moiety is carbon i-6, such as acetic acid.

Propionic acid, caproic acid, etc., where the alcohol moiety is the second
Examples of the alcohol include 3-butyn-2-ol, 4-pentyn-2-ol, and 7-octyn-6-ol.

The alcohol used in the present invention is, for example, methanol,
Ethanol, 0-propertool, 2-propertool, n
-Butanol, inbutanol, etc. can be used because of their reactivity and stability of the enzyme.

Most preferred are aliphatic alcohols having 3 or 4 carbon atoms.

The enzyme used in the present invention is preferably one called lipase, riboprotein lipase, or esterase. The type of enzyme does not matter as long as it has the ability to cause an asymmetric alcoholysis reaction with the enzyme. Commercially available enzymes include those listed below.

In addition, these hydrolytic enzymes may be purified products or crude products, and their forms include powdered or granular hydrolytic enzymes, or microbial cells that produce hydrolytic enzymes (processed curved bodies, resting bodies, or still bodies). ) can be used.

Further, the dilatation carrier 1 may include molecules such as polystyrene, polypropylene, starch, and gluten, activated carbon, porous glass, celite, zeolite, kaolinite, bentonite, alumina, silica gel, hydroxyapatite, and calcium phosphate.

It is also possible to use an immobilized enzyme obtained by supporting and immobilizing the above-mentioned hydrolase on an inorganic material such as a metal oxide by a physical adsorption method and drying it. Further, after the completion of one reaction, the ry/li4 collected by filtration from the reaction solution retains sufficient activity and stereoselectivity of the reaction.

It is possible to reuse it repeatedly, and it is also possible to use the enzyme for continuous reactions.

The organic solvent used in the present invention does not dissolve the enzyme.
Any substance can be used as long as it can control the activity. Examples of such organic solvents include, in addition to the alcohols listed above, saturated hydrocarbons such as pentane, hexane, and octane, halogenated hydrocarbons such as dichloromethane, chloroform, and carbon tetrachloride, benzene, toluene, xylene, etc. aromatics, esters such as methyl acetate, ethyl acetate, propyl acetate, propatool, isopropanol, butanol, isobutanol,
Examples include alcohols such as tertiary butanols, but hexane, carbon tetrachloride, benzene, and alcohols are preferably used from the viewpoint of reaction promotion.

The asymmetric alcoholysis reaction of the (R,S)-ester represented by the general formula (1) is carried out by mixing the (R,S)-ester with alcohol in the organic solvent such as hexane or carbon tetrachloride. , so that both can be brought into efficient contact with the enzyme.

The reaction temperature is suitably 5 to 100°C, particularly preferably 20 to 45°C. The reaction time is generally 1 to 5
00 hours, but can be appropriately selected by raising the reaction temperature, increasing the substrate concentration, or increasing the amount of enzyme.

The ratio of the (R,S)-ester represented by the general formula (II) to the alcohol used is 1:0.5 to 1:10 (1:0.5 to 1:10).
The molar ratio is preferably 1:0.6 to 1:2 (molar ratio).

In the present invention, after carrying out the asymmetric alcoholysis reaction in this manner, the enzyme can be easily removed by a conventional washing operation, etc., and can be reused as is.

Ester and alcohol can be separated from the reaction solution (filtrate) by distillation, extraction, column, etc., and ester can be converted to alcohol by normal alkaline decomposition.

In this way, the desired R-isomer and 3-isomer of optically active alkyl alcohol can be obtained.

〔Effect of the invention〕

Since the present invention has the above configuration, it has the following effects.

(1) Since this reaction uses a hydrophobic organic solvent, the reaction takes place at a high concentration, which improves the yield.

(2) Since this reaction is a slightly aqueous reaction, virtually no hydrolysis reaction occurs.

(3) Enzymes are insoluble in organic solvents and can be recovered and reused.

(4) Generally, bacterial contamination does not occur.

(5) The reaction is relatively low temperature and does not require special equipment or materials.

(6) A highly pure optically active substance can be obtained through a one-step reaction.

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples.

Example 1 4 g of enzyme (Amano Pharmaceutical, lipase "Amano" PS) and (
R.

5) Pour a solution of 5 g (45 mmol) of -3-acetoxy-1-butyne and 5 g (68 mmol) of inbutanol dissolved in hexane IO into an Erlenmeyer flask,
Stir for 3 g at 30° C. and 150 rpm. After the reaction has stopped,
After removing the enzyme by filtration and washing with water, 3-acetoxy-1
-butin was obtained.

This ester was analyzed by high performance liquid chromatography using optically active color 11 (on ChiraRacel 0) using hexane as an eluent, and the enantiomers could be separated and analyzed.As a result, the ester obtained by the enzymatic reaction was analyzed. ,
The enantiomer with longer retention time was extremely reduced, and the optical purity of the enantiomer with shorter retention time was 80%.

Example 2 4 g of enzyme (Amano Pharmaceutical, lipase "Amano" CES),
(R8)-4-propylcarbonyloxy-1-pentyne 7°4g (48■■oQ) and isobutanol 7.
A solution of 1 g (96-■oQ) dissolved in 25-hexane was placed in an Erlenmeyer flask and stirred at 30°C and 150 rpm for 3 days. After the reaction has stopped.

The enzyme was removed by filtration, and after washing with water, the solvent was distilled off under reduced pressure. The residue contains 50 a of methanol and 0.1 g of concentrated HCQ.
Add 30 B,! After carrying out the reduction, 2 g of 1-pentyn-4-ol was obtained by distillation.

The benzoylated alkyne alcohol was subjected to high performance liquid chromatography using an optically active column (Chiralasell OB) using hexane as an eluent to separate and analyze the ethylene thiomer. As a result, in the alkyne alcohol obtained by this enzymatic reaction, the ethylene thiomer with the longer retention time had disappeared, and the optical purity of the ethylene thiomer with the shorter retention time was 99% or more.

Example 3 4 g of enzyme (Tenju Pharmaceutical, lipase “Amano JCES)”
(1'l,5)-3-propylcarbonyloxy-1-
Octine 7.8 g (40 ■■ oQ), and isobutanol 4.4 g (60 Peng Il.

A solution of Q) dissolved in 100-hexane is placed in an Erlenmeyer flask and stirred for 3 g at 30°C and 150 rps+.

After stopping the reaction, the enzyme was removed by filtration, and after washing with water, optically active 3-propylcarbonyloxy-1-octyne was obtained. The optical purity of this ester was the same as in Example 2.

Claims (1)

[Claims] (1) The following general formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (l=0~4, m=0 or 1, n=0~4, C^*=
Existence of an enzyme that has the ability to act on (R,S)-ester represented by an asymmetric carbon (asymmetric carbon) and perform an asymmetric alcohololysis reaction with either the R-form or the S-form ester preferentially with alcohol. Below, the (R,S)-ester represented by the above general formula (I) and alcohol are reacted in an organic solvent to perform an alcoholysis reaction, resulting in the following general formula (II) ▲ Numerical formula, chemical formula, table, etc. ▼(II) (I = 0 to 4, m = 0 or 1, C^* = asymmetric carbon) It is possible to split into an optically active alcohol enriched in either the R-form or the S-form. A method for producing a characteristically optically active secondary alkyne alcohol.