PROCESS FOR PRODUCING AN OPTICALLY ACTIVE 2-ARYL-3-ACYLOXY-1,2-PROPANEDIOL

Abstract: A novel glycerol derivative and a process for producing the same, and a process for producing a triazole derivative. Specifically the invention provides an optically active 2-arylglycerol derivative that is novel and useful as an intermediate for drug synthesis, and the invention process can provide (R)-2-(2,4-difluorophenyl)-3-(1H-1,2,4-triazole-1-yl)propane-1,2-diol useful as an antifungal agent.

Description: The present invention relates to a process for preparing a glycerol derivative. More particularly, the invention relates to a process for preparing an optically active glycerol derivative, being useful as a raw material for synthesizing a medicament, an agricultural chemical or the like. BACKGROUND ART Hitherto, a compound useful as a raw material of a medicament or biologically active substance has been variously studied. However, there was no suitable compound from various viewpoint of economy and industry, according to demands for a glycerol derivative and an acetone derivative which can be used as a raw material for synthesizing a medicament, an agricultural chemical or the like. For instance, 1-chloro-2-(2,4-difluorophenyl)-2, 3-epoxypropane is synthesized by carrying out ring closure of epoxide using 1, 3-dichloro-2-(2,4-difluorophenyl)-2-propanol in the presence of sodium hydride in dimethylformamide, in Japanese Unexamined Patent Publication No. 9183/1993. However, this reaction had problems in industrially carrying out the reaction such as evolution of hydrogen and difficult removal of dimethvlformamide after completion of the reaction. Wang, Z.M. et al., Synlett 1993, No. 8, p. 603-604 and Blundell, P. et al., Synlett 1994, No. 4, p. 263-265 disclose methods for enantioselective synthesis of compounds of formula (VIII) defined below. However, these methods do not employ microorganisms or enzymes. There is no report that the optically active 2-aryl-3-acyloxy-1,2-propandediol represented by the formula (VIII): has been synthesized using microorganisms or enzymes. The object of the present invention is to provide a process for preparing optically active 2-aryl-3-acyloxy-1,2-propanediols. The present invention relates to a process for preparing an optically active 2-aryl-3-acyloxy-1,2-propanediol, which comprises allowing to act a microorganism or an enzyme having enzyme activity which allow to form an optically active 2-aryl-3-acyloxy-1, 2-propanediol represented by the formula (VIII): wherein Ar is an aryl group which may be substituted, R is a normal chain or branched chain alkyl group, a normal chain or branched chain alkenyl group which may be substituted or an aryl group which may be substituted by stereospecific hydrolysis of an 2-aryl-1,3-diacyloxy-2-propanol represented by the formula (I): wherein each of Ar and R is the same as each of the defined above, on an 2-aryl-1, 3-diacyloxy-2-propanol represented by the formula (I) and allowing to form an optically active 2-aryl-3-acyloxy-1,2-propanediol represented by the formula (VIII). Herein, the above process wherein Ar is 2, 4-difluorophenyl group, R is a normal chain or branched chain alkyl group, or phenyl group; further the above process wherein R is methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, isopropyl, isobutyl, chloromethyl, β-chloroethyl or γ -chloropropyl group are preferable, and the above process wherein R is isopropyl group and the above process wherein Ar is phenyl, 4-fluorophenyl, 4-chlorophenyl, 4-methylphenyl, 4-methoxyphenyl, 4-biphenyl, 4-tert-butylphenyl, 2-chlorophenyl, 2-methylphenyl, 2, 4-dichlorophenyl, 2, 4-difluorophenyl, 2, 4-dimethylphenyl, 1-naphthyl or 2-naphthyl group are more preferable. Additionally, the above process wherein the microorganism or enzyme which hydrolyzes stereospecifically is a member selected from the group consisting of the microorganism belonging to Chromobacterium genus, Rhizopus genus, Mucor genus, Candida genus, Aspergillus genus, Geotrichum genus, Pseudomonas genus, Bacillus genus or Humicola genus, the enzyme derived from that microorganism and the enzyme derived from porcine pancreas; the above process wherein the stereospecific hydrolysis is carried out in the presence of an organic solvent; the above process wherein the stereospecific hydrolysis is carried out at 15°C or below; and the above process wherein the stereospecific hydrolysis is carried out at pH 6 or below are preferable, and further the above process wherein the organic solvent is a hydrocarbon is preferable. Also, the present invention relates to a process for preparing an optically active 2-aryl-3-acyloxy-1, 2-propanediol, which comprises allowing to act a microorganism or an enzyme having enzyme activity which esterifies only hydroxy group at 1-position or 3-position stereospecifically on an 2-aryl-1, 2, 3-propanetriol represented by the formula (III): wherein Ar is an aryl group which may be substituted in the presence of an acylating agent and allowing to form an optically active 2-aryl-3-acyloxy-1,2-propanediol represented by the formula (VIII): wherein Ar is the same as the defined above, R is a normal chain or branched chain alkyl group which may be substituted, a normal chain or branched chain alkenyl group which may be substituted or an aryl group which may be substituted. Herein, the above process wherein Ar is 2, 4-difluorophenyl group, R is a normal chain or branched chain alkyl group, or phenyl group; the above process wherein the acylating agent is carboxylic acid, a carboxylic acid ester or a carboxylic acid anhydride; and the above process wherein the microorganisms or enzyme which esterifies stereospecifically is a member selected from the group consisting of the microorganism belonging to Chromobacterium genus, Rhizopus genus, Mucor genus, Candida genus, Aspergillus genus, Geotrichum genus, Pseudomonas genus, Bacillus genus or Humicola genus, the enzyme derived from that microorganism, the enzyme derived from porcine pancreas and the enzyme derived from wheat are preferable, further the above process wherein R is methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, isopropyl, isobutyl, chloromethyl, β-chloroethyl or γ-chloropropyl group is preferable. Examples of an aryl group represented by Ar in each compound of formulae (I) and (VIII), which may be substituted, in the present invention, are 2, 4-difluorophenyl, phenyl, 4-fluorophenyl, 4-chlorophenyl, 4-methylphenyl, 4-methoxyphenyl, 4-biphenyl, 4-tert-butylphenyl, 2-chlorophenyl, 2-methylphenyl, 2, 4-dichlorophenyl, 2, 4-dimethylphenyl, 1-naphthyl and 2-naphthyl group and particularly 2,4-difluorophenyl group is preferable. Examples of a normal chain or branched chain alkyl group which may be substituted, a normal chain or branched chain alkenyl group which may be substituted or an aryl group which may be substituted, represented by R, are preferably a normal chain or branched chain alkyl group having 1 to 10 carbon atoms, or phenyl group and particularly methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, isopropyl, isobutyl, chloromethyl, β -chloroethyl and γ -chloropropyl group are preferable and isopropyl group is more preferable. Preferable examples or the 2-aryl-1,3-diacyloxy-2-propanol represented by the formula (I): wherein Ar is the same as the defined above, are particularly 2-phenyl-1,3-diisobutyryloxy-2-propanol, 2-(4-fluorophenyl)-1, 3-diisobutyryloxy-2-propanol, 2-(4-chlorophenyl)-1,3-diisobutyryloxy-2-propanol, 2-( 4-methylphenyl)-1,3-diisobutyryloxy-2-propanol, 2-(4-methoxyphenyl)-1,3-diisobutyryloxy-2-propanol, 2-(4-biphenyl)-1,3-diisobutyryloxy-2-propanol, 2-(4-tert-butylphenyl)-1,3-diisobutyryloxy-2-propanol, 2-(2-chlorophenyl)-1,3-diisobutyryloxy-2-propanol, 2-( 2-methylphenyl)-1,3-diisobutyryloxy-2-propanol, 2-(2,4-difluorophenyl)-3-diisobutyryloxy-2-propanol, 2-(2,4-dichlorophenyl)-1,3-diisobutyryloxy-2-propanol, 2-(2,4-dimethylphenyl)-1,3-diisobutyryloxy-2-propanol, 2-(1-naphthyl)-1,3-diisobutyryloxy-2-propanol, and 2-(2-naphthyl)-1,3-diisobutyryloxy-2-propanol. By the following three kinds of processes for preparation is synthesized 2-aryl-1,3-diacyloxy-2-propanol represented by the formula (I). In the first process (shown in the following Reaction formula 1): wherein each Ar and R is the same as each of the defined above, M is Li, MgCl, MgBr or MgI, the 2-aryl-1,3-diacyloxy-2-propanol is obtained by allowing to react an organic metal compound such as 2,4-difluorophenyllithium, 2, 4-difluorophenylmagnesium chloride, 2,4-difluorophenylmagnesium iodide, 2,4-difluorophenylmagnesium bromide, phenylmagnesium bromide, 4-fluorophenylmagnesium bromide, 4-chlorophenylmagnesium bromide, 4-methylphenylmagnesium bromide, 4-biphenylmagnesium bromide, 4-methoxyphenylmagnesium bromide, 4-tert-butylphenylmagnesium bromide, 2-chlorophenylmagnesium bromide, 2-methylphenylmagnesium bromide, 2,4-dichlorophenylmagnesium iodide, 2, 4-dimethylphenylmagnesium bromide, 1-naphthylmagnesium bromide or 2-naphthylmagnesium bromide with 1,3-diacyloxyacetone represented by the formula (II): wherein R is the same as the defined above. The 2,4-difluorophenyllithium employed can be prepared by treating 2, 4-difluorobromobenzene, 2,4-difluorochlorobenzene or 2,4-difluoroiodobenzene with a base such as n-butyl lithium. Also, 2,4-difluorophenylmagnesium bromide, 2,4-difluorophenylmagnesium chloride, 2,4-difluorophenylmagnesium iodide, phenylmagnesium bromide, 4-fluorophenylmagnesium bromide, 4-chlorophenylmagnesium bromide, 4-methylphenylmagnesium bromide, 4-biphenylmagnesium bromide, 4-methoxyphenylmagnesium bromide, 4-tert-butylphenylmagnesium bromide, 2-chlorophenylmagnesium bromide, 2-methylphenylmagnesium bromide, 2,4-dichlorophenylmagnesium iodide, 2,4-dimethylphenylmagnesium bromide, 1-naphthylmagnesium bromide or 2-naphthylmagnesium bromide employed can be prepared by allowing to react 2,4-difluorobromobenzene, 2,4-difluorochlorobenzene, 2,4-difluoroiodobenzene, bromobenzene, 4-fluorobromobenzene, 4-chlorobromobenzene, 4-bromotoluene, 4-bromobiphenyl, 4-bromoanisole, 1-bromo-4-tert-butylbenzene, 2-chlorobromobenzene, 2-bromotoluene, 2,4-dichloroiodobenzene, 4-bromo-m-xylene, 1-bromonaphthalene and 2-bromonaphthalene, respectively with metal magnesium. The preferable solvents employed in the above process are usually ether solvents such as diethylether and THF. Alternatively, the solvent may be used by mixing a solvent which is inactive against a reaction for example, a reaction employing hexane, with the above solvent. The reaction is carried out at a temperature of -80° to reflux temperature of the solvent. In order to avoid decomposing a raw material or product, it is preferably carried out at -30°C or below. The amount of 1,3-diacyloxyacetone (II) is a range of 1 to 1.2 equivalents to that of an organic metal compound. After the reaction is finished, the reaction mixture was added to an acid aqueous solution under ice cooling with keeping pH accescence and then, the resulting liquid was extracted with an organic solvent such as ethyl acetate to give the desired product readily. As to the process for preparing 1,3-diacyloxyacetone (II), 1, 3-diacyloxyacetone is obtained by allowing to react dihydroxyacetone monomer or dimer in the presence of a base with acid anhydride or acid halide. The reaction can be carried out without a solvent but it is preferable to employ organic solvents such as halogenated hydrocarbon, for example, methylene chloride, chloroform, carbon tetrachloride and the like, or aromatic hydrocarbons, for example, benzene, toluene, xylene and the like. To the reaction liquid, 2 or more equivalents of base to that of dihydroxyacetone dimer may be added. Examples of the bases are tertiary amines such as triethylamine, trimethylamine, diisopropylethylamine, N,N-dimethylaniline and N,N-diethylaniline; aromatic nitrogen compounds such as pyridine, 4-(N,N-dimethylamino)pyridine, imidazole, 2,6-lutidine, sodium hydride and potassium hydride. The reaction temperature can be employed at broad temperature range and usually a temperature of -10°C to a reflux temperature of the solvent is employed. After the reaction is finished, to the resulting liquid is added a water which contains a base such as acid, alkali or ammonium chloride with keeping pH of the reaction liquid around neutral. And then, the resulting liquid is extracted with an organic solvent such as ethyl acetate to give the desired product readily. As to the process for preparing 1,3-diacetoxyacetone, a process wherein 1, 3-diacetoxyacetone is synthesized by employing dihydroxyacetone dimer, and acetyl chloride or acetic acid anhydride is known (ref. the reference by Hiroshi Suemune, Chemical Pharmaceutical Bulletin, 34 (8), 3440 (1986)). According to the second process (shown in the following Reaction formula 2): the 2-aryl-1, 3-diacyloxy-2-propanol represented by the formula (I): wherein Ar is an aryl group which may be substituted, R is a normal chain or branched chain alkyl group which may be substituted, a normal chain or branched chain alkenyl group which may be substituted or an aryl group which may be substituted is obtained by carrying out position-specifically 1,3-diacylation by allowing to react an acid halide, an acid anhydride or an ester represented by the formula (IV): wherein R is the same as the defined above, X 1 is a halogen atom, a normal chain or branched chain acyloxy group or a normal chain or branched chain alkoxy group with an aryl-1,2,3-propanetriol represented by the formula (III): wherein Ar is the same as the defined above. In the above reaction, 2 or more equivalents of compound represented by the formula (IV) to that of compound of the formula (III) may be employed. In case the acid halide or the acid anhydride is employed, if necessary, to the reaction liquid may be added a tertiary amine such as triethylamine, trimethylamine, diisopropylethlyamine, N,N-dimethylaniline or N,N-diethylaniline; and an aromatic nitrogen compound such as pyridine, imidazole or 2,6-lutidine or sodium methoxide, sodium ethoxide, sodium hydride or potassium hydride. In case the ester is employed, if necessary, to the reaction liquid may be added hydrochloric acid, sulfuric acid or phosphoric acid as an acid catalyst and while may be added sodium methoxide, sodium ethoxide, sodium hydride or potassium hydride as an alkali catalyst. The above reaction can be carried out without a solvent but it is preferable to carry it out in an organic solvent such as halogenated hydrocarbon, for example, methylene chloride, chloroform or carbon tetrachloride; aromatic hydrocarbon, for example, benzene, toluene or xylene; or dimethylformamide. The reaction temperature can be employed at broad temperature range and usually a temperature of -10° to -40°C is employed in order to carry out position-specifically 1,3-diacylation because acylation of hydroxyl group at 2-position occurs at high temperature. After the reaction is finished, to the resulting liquid is added water which contains an acid, an alkali or a base such as ammonium chloride with keeping pH of the reaction liquid around neutral. And then, the resulting liquid is extracted with an organic solvent such as ethyl acetate to give the desired product readily. According to the third process (shown in the following Reaction formula 3): the 2-aryl-1, 3-diacyloxy-2-propanol represented by the formula (I): wherein Ar is an aryl group which may be substituted, and R is a normal chain or branched chain alkyl group which may be substituted, a normal chain or branched chain alkenyl group which may be substituted or an aryl group which may be substituted is obtained by allowing to react a 1-chloro-2-arylphenyl-2,3-epoxypropane represented by the formula (VI): wherein Ar is the same as the defined above with a carboxylic acid represented by the formula (VII): RCOOH wherein R is the same as the defined above and its salt. The 1,3-dichloro-2-aryl-2-propanol (V) being the raw material of the above reaction, for example, in case of 1,3-dichloro-2-(2,4-difluorophenyl)-2-propanol, is obtained by allowing to react 2, 4-difluorobromobenzene with 1,3-dichloroacetone in an organic solvent such as anhydrous ether or hexane at the presence of a base such as n-butyllithium, according to the known process by references (ref., for example, Japanese Unexamined Patent Publication No. 32868/1983). The above 1-chloro-2-aryl-2, 3-epoxypropane (VI) is obtained by dissolving 1,3-dichloro-2-aryl-2-propanol (V) in a halogenated hydrocarbon such as methylene chloride, chloroform or carbon tetrachloride; or an aromatic hydrocarbon such as benzene, toluene or xylene, and then, thereto is added an aqueous solution which contains 1 or more equivalents basic substance such as lithium hydroxide, sodium hydroxide or potassium hydroxide, to that of compound (V) to be allowed to react in two phase. Also, an after-treatment may be only separation of organic layer from water layer. The above 2-aryl-1,3-diacyloxy-2-propanol of the formula (I) is obtained by allowing to react 1-chloro-2-(2, 4-difluorophenyl)-2, 3-epoxypropane (VI) with a carboxylic acid of the formula (VII) and its salt. The amount of the above carboxylic acid is 5 or more equivalents to that of compound (VI) and preferably 2 to 5 equivalents to that of compound (VI). The reaction temperature can be employed at broad temperature range. In order to raise reaction rates, the temperature is employed at 80°C or more, and preferable at 100°C or more. After the reaction is finished, the resulting reaction liquid is distilled under reduced pressure to remove carboxylic acid or to the resulting reaction liquid wherein acid is neutralized is added water and then the liquid is extracted with the organic solvent. It is preferable that a salt of carboxylic acid is an alkali metal salt, an alkaline earth metal salt or an amine salt of carboxylic acid and more preferable that the salt of carboxylic acid is lithium salt, sodium salt, potassium salt, magnesium salt, calcium salt, ammonium salt, trimethylammonium salt, triethylammonium salt, tetramethylammonium salt or tetraethylammonium salt of carboxylic acid. As a result of further vigorous effort by the present inventors on examination of a process for preparing an optically active 2-arylglycerol derivative, a microorganism and enzyme having an enzymatic activity which hydrolyzes stereospecifically the 2-aryl-1,3-diacyloxy-2-propanol represented by the formula (I) to form the optically active 2-aryl-3-acyloxy-1,2-propanediol represented by the formula (VIII), and an enzymatic activity which esterifies stereospecifically only one side hydroxyl group at 1-position or at 3-position of 2-aryl-1,2, 3-propanetriol represented by the formula (III) in the presence of an acylating agent, has been found. The industrial process for preparing the optically active 2-aryl-3-acyloxy-1,2-propanediol which includes the compound represented by the formula (VIII), being useful as an intermediate of a medicament has been established the present invention. That is, the compound represented by the formula (VIII) is synthesized by allowing to act a microorganism or an enzyme having enzymatic activity which allow to form the optically active 2-aryl-3-acyloxy-1, 2-propanediol 5 represented by the formula (VIII) by stereospecific hydrolysis of the 2-aryl-1, 3-diacyloxy-2-propanol represented by the formula (I): wherein each of Ar and R is the same as each of the defined above, on the 2-aryl-1,3-diacyloxy-2-propanol represented by the formula (I). Examples of microorganisms or enzymes employed in the present invention can be any microorganism, animal tissue or enzyme which is separated therefrom, which has activity that stereospecifically hydrolyzes the 2-aryl-1, 3-diacyloxy-2-propanol represented by the formula (I) to form the optically active 2-aryl-3-acylory-1, 2-propanediol represented by the formula (VIII). Those microorganisms, animal tissues and enzymes having the above activity can be searched by the method shown in the following Example 28. The concrete examples of the microorganisms or enzymes are Chromobacterium genus, Rhizopus genus, Mucor genus, Candida genus, Aspergillus genus, Geotrichum genus, Pseudomonas genus, Bacillus genus and Humicola genus, and the enzymes derived from those microorganisms, the enzymes derived from mammalian viscera, and more detail, are Chromobacterium viscosum , Rhizopus delemar , Rhizopus javanicus , Mucor javanicus , Candida antarctica , Aspergillus niger, Geotrichum candidum , Pseudomonas fluorescens , Bacillus sp ., Humicola sp . and the enzymes derived from porcine pancreas. The commercially available enzymes thereof are shown in Tables 1 and 2. The enzymes may be employed in accordance with whether a form of the desired compound is R-form or S-form. In the process for preparing the optically active compound represented by the formula (VIII) by carrying out stereospecifically hydrolysis of the substrate represented by the formula (I), the hydrolysis reaction is carried out the following steps. The substrate is suspended in water or buffer in a preferable range of 0.1 % to 90 % (w/v) and then, suitable enzyme, for example at a range of 1:1 to 500:1 (weight ratio of substrate and enzyme) is added to the resulting suspension with stirring at a temperature of 10° to 45°C, preferable 5° to 15°C. In case of alkaline condition, a main constituent is readily racemized and the optical purity thereof falls, therefore, the pH is preferably in a range of 3 to 6. Alternatively, according to a progress of the hydrolysis, the pH of the reaction liquid tends towards the acidic side, therefore, the pH may be kept by suitable alkaline solution such as sodium hydroxide. Further, in order to stimulate a progress of the reaction, the organic solvents which do not inhibit the enzyme reaction may be optionally added to the reaction liquid. Examples of the solvents are n-hexane, cyclohexane, methylcyclohexane, n-heptane, n-octane, isooctane, n-decane, benzene, toluene, chloroform, petroleum ether and diisopropyl ether and more preferably is hydrocarbon. Also, the enzymes can be used by immobilizing on suitable water-insoluble carriers such as ion-exchange resin. After the hydrolysis, in order to isolate an 2-aryl-3-acyloxy-1,2-propanediol, being product from the reaction liquid, the general isolation method can be employed. For example, extraction is carried out by addition of an organic solvent such as ethyl acetate to the reaction liquid. After the resulting liquid is dried, the organic solvent is removed under reduced pressure. As the result, the optically active 2-aryl-3-acyloxy-1,2-propanediol can be obtained. Furthermore, it can be purified in high purity by purification procedures such as crystallization, distillation and column chromatography on silica gel. The optically active compound represented by the formula (VIII) is synthesized by allowing to act a microorganism or an enzyme having enzymatic activity which esterifies only hydroxyl group at 1-position or at 3-position stereospecifically on an 2-aryl-1, 2, 3-propanetriol represented by the formula (III): wherein Ar is the same as the defined above and acylating agent. The process for preparing the 2-aryl-1,2,3-propanetriol represented by the formula (III) being a raw material in the process of the present invention is described later. As examples of enzymes used in the present invention there can be employed any microorganism, animal tissue or enzyme which is separated therefrom, which has an activity that esterifies stereospecifically only the hydroxyl group at 1-position or 3-position on an 2-aryl-1, 2, 3-propanol represented by the formula (III) in the presence of an acylating agent, allowing to form an optically active 2-aryl-3-acyloxy-1,2-propanediol represented by the formula (VIII). The concrete examples of enzymes are the same as the above enzymes having stereospecifically hydrolyzing activity or enzymes derived from wheat. Examples of acylating agent employed in the present invention are carboxylic acids such as acetic acid and butyric acid and carboxylic acid esters such as ethyl acetate, ethyl propionate and vinyl acetate, carboxylic anhydrides such as acetic anhydride, butyric anhydride, fumaric acid, maleic acid and benzoic acid. The esterification is carried out by the following steps. The substrate is suspended in an organic solvent in a preferable range of 0.1 % to 90 % (w/v) and then, suitable enzyme, for example at a range of 1:1 to 500:1 (weight ratio of substrate and enzyme) is added to the resulting suspension with stirring at a temperature of 10° to 45°C, preferable 15° to 35°C. The acylating agent itself can be employed as a solvent and, if necessary, the reaction may be carried out in other organic solvent. Examples of the solvents are toluene, hexane, acetone, diisopropyl ether and dichloromethane. The above solvent can be employed alone or mixed with each other. Also, the enzymes can be employed by immobilizng on suitable water-insoluble carriers such as ion-exchange resin. After the esterification, in order to isolate the 2-aryl-3-acyloxy-1,2-propanediol, being product from the reaction liquid, the general isolation method is employed. For example, if necessary, the reaction liquid is filtrated to remove insoluble enzyme and extracted with organic solvent such as ethyl acetate. After the resulting liquid is dried over anhydrous sodium sulfate and the like, the organic solvent is removed under reduced pressure. As the result, the desired optically active 2-aryl-3-acyloxy-1,2-propanediol can be obtained. Furthermore, it can be purified in high purity by purification procedures such as column chromatography on silica gel, crystallization and distillation. In order to prepare the 2-aryl-1, 2,3-propane triol represented by the formula (III), it is possible to hydrolyze 2-aryl-1,3-diacyloxy-2-propanol represented by the formula (I) or 2-aryl-3-acyloxy-1, 2-propanediol represented by the formula (VIII) in the presence of a strong base such as KOH or NaOH, or to hydrolyze it by enzyme having activity which hydrolyzes it non-stereospecifically. Examples of the above enzymes are Aspergillus genus, lipase obtained from embryo of wheat and cellase obtained from Trichloroderma genus. Examples of those enzymes as a commercially available enzyme are Lipase AP-6 (made by Amano Pharmaceutical Co., Ltd.) and Lipase (type I) (made by Sigma Chemical Company). The hydrolysis by enzyme can be accomplished using the above enzymes by the same procedure as the process of stereospeficially hydrolysis described above. For example, by hydrolysis of 2-(2,4-difluorophenyl)-1,3-diacyloxy-2-propanol or 2-(2,4-difluorophenyl)-3-acyloxy-1,2-propanediol in the presence of a strong base such as KOH or NaOH, or by hydrolysis it by enzyme having activity which hydrolysis it non-stereospecifically, 2-(2,4-difluorophenyl)-1,2,3-propanetriol can be prepared. This 2-aryl-1,2,3-propanetriol can be isolated as a highly purified compound by extraction with ethyl acetate from reaction liquid and by removing the solvent and then by purification by column chromatography on silica gel. BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention is more specifically explained on the basis of the following Examples, but is not limited to only these Examples. Preparation EXAMPLE 1 Synthesis of 1,3-diacetoxy-2-(2,4-difluorophenyl)-2-propanol (according to Reaction formula 1) Under an atmosphere of argon, 850 mℓ of THF solution of 2, 4-difluorophenylmagnesium bromide prepared from 202.6 g (1.05 mol) of 2,4-difluorobromobenzene and 26.7 g (1.1 mol) of magnesium turnings was added dropwise at -30°C to 1.7 ℓ of THF solution of 174 g (1.00 mol) of 1,3-diacetoxyacetone which was previously cooled to -30°C. After the resulting liquid was stirred at -60°C for 2 hours, a temperature thereof was gradually raised to room temperature. Then, to the reaction mixture was added 1 ℓ of 1.2 N aqueous solution of hydrochloric acid at 5°C or below, and an aqueous layer was extracted twice with 1 ℓ of ethyl acetate. The organic layer was washed with saturated aqueous solution of sodium chloride, dried and concentrated under reduced pressure to give 302 g of crude oil. The obtained oil was purified by means of column chromatography on silica gel (hexane : ethyl acetate = 1:1) to give 125 g of the desired compound. The compound was recrystallized from toluene/hexane. m. p. : 70. 5° - 71. 5°C IR ν cm -1 : 3403, 1744, 1240, 1042, 849 1 H-NMR (400MHz, CDCl 3 ) δppm: 7. 70-7. 67 (m ; 1H), 6. 93 (t ; J=5. 37Hz, 1H), 6. 81 (t ; J=2. 93Hz, 1H), 4. 52 (d ; J=11. 72Hz, 2H), 4. 44 (d; J=11. 72Hz, 2H), 3. 65 (s; 1H), 2. 03 (s ; 6H) Preparation EXAMPLE 2 Synthesis of 1,3-diacetoxy-2-(2,4-difluorophenyl)-2-propanol (according to Reaction formula 1) The reaction was carried out in the same manner as described in Preparation Example 1 except that diethyl ether was employed instead of THF as a solvent. From 202.6 g of 2,4-difluorobromobenzene was prepared 100 g of the desired compound. Preparation EXAMPLE 3 Synthesis of 1, 3-diacetoxy-2-(2,4-difluorophenyl)-2-propanol (according to Reaction formula 1) Under an atmosphere of argon, 22.5 g of 2,4-difluorobromobenzene was dissolved in 200 mℓ of diethyl ether and to the resulting solution was added dropwise 73 mℓ of 1.63 M n-hexane solution of n-butyllithium at -30°C. The resulting liquid was stirred for 1 hour and stored at -60°C. This liquid was carefully added dropwise using an injection syringe to 150 mℓ of diethyl ether solution of 17.4 g of 1,3-diacetoxyacetone which was previously cooled to -30°C. After the resulting liquid was stirred at -60°C for 2 hours, a temperature thereof was gradually raised to room temperature. Then, the reaction mixture was transferred to 100 mℓ of 1.2 N aqueous solution of hydrochloric acid at 5°C or below, and the organic layer was separated therefrom and the aqueous layer was extracted twice with 100 mℓ of ethyl acetate. The organic layers were combined and washed with saturated aqueous solution of sodium chloride, dried over anhydrous magnesium sulfate. The resulting organic layer was filtered and the solvent was removed under reduced pressure. Thus obtained concentrate was purified by column chromatography on silica gel (hexane : ethyl acetate = 1:1) to give 8 g of the desired compound. Preparation EXAMPLE 4 Synthesis of 1,3-diacetoxy-2-(2,4-difluorophenyl)-2-propanol (according to Reaction formula 2) In 100 mℓ of pyridine was dissolved 10 g of 2-(2,4-difluorophenyl)-1, 2, 3-propanetriol. To the resulting solution was added dropwise 1.1 g of acetic anhydride at room temperature. After the dropping, the resulting liquid was stirred at room temperature for 1 hour. Then, to the reaction mixture was added 50 mℓ of ethyl acetate, and an organic layer was separated therefrom. After that the organic layer was washed with IN aqueous solution of hydrochloric acid and further washed with water and saturated aqueous solution of sodium chloride. Then the organic layer was dried over anhydrous sodium sulfate. The resulting organic layer was filtered and the solvent was removed under reduced pressure. Thus obtained concentrate was purified by column chromatography on silica gel (hexane : ethyl acetate = 1:1) to give 12.5 g of the desired compound. Preparation EXAMPLE 5 Synthesis of 1-chloro-2-(2,4-difluorophenyl)-2,3-epoxypropane (according to Reaction formula 3) To 1.7 ℓ of toluene solution of 433 g of 1, 3-dichloro-2-(2,4-difluorophenyl)-2-propanol was added 870 mℓ of 20 % aqueous solution of potassium hydroxide. After the resulting liquid was stirred at room temperature for 3 hours, the organic layer was separated therefrom The aqueous layer was extracted twice with 1 ℓ of ethyl acetate. The organic layers were combined and dried over anhydrous sodium sulfate. The resulting organic layer was filtered and the solvent was removed under reduced pressure. Thus obtained concentrate was distilled under reduced pressure to give 184 g of the desired compound. b. p. : 125° -13 5°C/30mmHg 1 H-NMR (90MHz, CDCl 3 ) δppm: 7. 57-7. 31 (1H, m), 6. 98-6. 71 (2H, m) , 4. 09 (1H, d, J=11. 9Hz), 3. 68 (1H, d, J=11. 9Hz), 3. 2 0 (1H, d, J=4. 8Hz), 2. 93 (1H, d, J=4. 8Hz) IR ν cm -1 : 1619, 1602, 1508, 1425, 1272 Preparation EXAMPLE 6 Synthesis of 1,3-diacetoxy-2-(2, 4-difluorophenyl)-2-propanol (according to Reaction formula 3) To 105 g of 1-chloro-2-(2,4-difluorophenyl)-2,3-epoxypropane were added 525 mℓ of acetic acid and 126 g of potassium acetate and the resulting mixture was stirred at 115°C for 15 hours. The reaction mixture was allowed to cool to room temperature. Then, to this reaction liquid was added 700 mℓ of water and a solid matter was dissolved and the resulting solution was extracted three times with 500 mℓ of ethyl acetate. The organic layer was washed with saturated aqueous solution of sodium hydrogencarbonate and with water and dried over anhydrous sodium sulfate. The resulting organic layer was filtered and the solvent was removed under reduced pressure. Thus obtained concentrate was purified by column chromatography on silica gel (hexane : ethyl acetate = 1:1) to give 100 g of the desired compound. Preparation EXAMPLE 7 Synthesis of 1,3-diacetoxyacetone Under an atmosphere of argon, 90 g of 1,3-dihydroxyacetone dimer and 250 mg of 4- (N,N-dimethylamino)pyridine were dissolved in 250 mℓ of pyridine. To the resulting solution, 225 mℓ of acetic anhydride was added dropwise at room temperature over 1 hour. After the resulting liquid was stirred at room temperature for 30 minutes, thereto was added 50 mℓ of methanol and the resulting liquid was further stirred at room temperature for 30 minutes. The solvent was removed under reduced pressure and the residue was subjected to a recrystallization from ether-petroleum ether to give 190 g of the desired compound. m. p. : 45. 5° -46. 6°C 1 H-NMR (400MHz, CDCl 3 ) δppm: 2. 18 (s, 6H), 4. 76 (s, 4H) IR ν cm -1 : 1770, 1745, 1230 Preparation EXAMPLE 8 Synthesis of 1,3-di-n-butyryl oxyacetone Under an atmosphere of argon, 45 g of 1, 3-dihydroxyacetone dimer and 100 mg of 4-(N,N-dimethylamino)pyridine were dissolved in 120 mℓ of pyridine. To the resulting solution, 196 mℓ of n-butyric anhydride was added dropwise at room temperature over 1 hour. After the resulting mixture was stirred at room temperature for 30 minutes, thereto was added 50 mℓ of methanol and the resulting mixture was further stirred at room temperature for 30 minutes. To the reaction mixture was added 1 ℓ of ethyl acetate and the organic layer was separated. The organic layer was washed with 2N HCl and further washed with saturated aqueous solution of sodium hydrogencarbonate and saturated aqueous solution of sodium chloride, and dried over anhydrous sodium sulfate. The solvent was removed under reduced pressure. The residue was subjected to a recrystallization from ether/n-hexane to give 98.6 g of the desired compound. m. p. : 47° - 48°C 1 H-NMR (400MHz, CDCl 3 ) δppm: 4. 76 (s, 4H), 2. 42 (t, 4H, J=7, 3Hz), 1. 65-1. 75 (m, 4H), 0. 99 (t, 6H, J=7. 3Hz) IR ν cm -1 : 1736, 1418, 1179, 1094, 994 Preparation EXAMPLE 9 Synthesis of 1,3-dipropionyloxyacetone Under an atmosphere of argon, 45 g of 1,3-dihydroxyacetone dimer and 100 mg of 4-(N,N-dimethylamino)pyridine were dissolved in 120 mℓ of pyridine. To the resulting solution, 150 mℓ of propionic anhydride was added dropwise at room temperature over 1 hour. After the resulting liquid was stirred at room temperature for 30 minutes, thereto was added 50 mℓ of methanol and the resulting liquid was further stirred at room temperature for 30 minutes. To the reaction mixture was added 1 ℓ of ethyl acetate and the organic layer was separated. The organic layer was washed with 2N HCl and further washed with saturated aqueous solution of sodium hydrogencarbonate and saturated aqueous solution of sodium chloride, and dried over anhydrous sodium sulfate The solvent was removed tinder reduced pressure. The residue was subjected to a recrystallization from ether/n-hexane to give 74 g of the desired compound. 1 H-NMR (400MHz, CDCl 3 ) δppm:4. 77 (s, 4H), 2. 47 (q, 4H, J=7. 3Hz), 1. 19 (t, 6H, J=7. 3Hz) Preparation EXAMPLE 10 Synthesis of 1,3-diisobutyryloxyacetone A 100 mℓ reaction vessel was charged with 4.18 g of dihydroxyacetone (monomer), 11.2 mℓ of pyridine and 10 mg of 4-dimethylaminopyridine and the mixture was stirred at room temperature. Thereto was added dropwise 16.7 mℓ of isobutyric anhydride over 30 minutes. After the dropping, the resulting liquid was further stirred for 1 hour and then 1 mℓ of methanol was added thereto and the resulting liquid was further stirred for 1 hour. To the reaction mixture was added ethyl acetate and the organic layer was separated. The organic layer was washed with water and further washed with saturated aqueous solution of sodium bicarbonate and 1N HCl. Then, the solvent was removed under reduced pressure. The residue was distilled under reduced pressure to give 7.47 g of the desired compound. b. p. 91° -103°C/0. 5mmHg 1 H-NMR (400MHz, CDCl 3 ) δppm: 4. 76 (4H, s), 2. 72-2. 65 (2H, m) , 1. 24-1. 22 (12H, d) Preparation EXAMPLE 11 Synthesis of 1,3-dipropionyloxy-2-(2,4-difluorophenyl)-2-propanol (according to Reaction formula 2) In 30 mℓ of pyridine was dissolved 3.06 g of 2-(2,4-difluorophenyl)-1, 2, 3-propanetriol and thereto was added dropwise 4.29 g of propionic anhydride and stirred at room temperature for 6 hours. To thus obtained reaction liquid was added 100 mℓ of ethyl acetate and the organic layer was separated. The organic layer was washed with 1N HCl and further washed with water and saturated aqueous solution of sodium chloride. After the organic layer was dried over anhydrous sodium sulfate, the solvent was removed under reduced pressure. Thus obtained concentrate was purified by means of column chromatography on silica gel (hexane/ethyl acetate = 2/1) to give 4.55 g of the oily desired compound. 1 H-NMR (400MHz, CDCl 3 ) δppm: 7. 71-7. 67 5 (1H, m) , 6. 94-6. 89 (1H, m) , 6. 83-6. 78 (1H, m) , 4. 54-4. 43 (4H, dd), 3. 77 (1H, s), 2. 32-2. 26 (2H, q), 1. 08-1. 0 4 (3H, t) Preparation EXAMPLE 12 Synthesis of 1, 3-di-n-pentanoyl-2-(2,4-difluorophenyl)-2-propanol (according to Reaction formula 2) In 30 mℓ of pyridine was dissolved 3.06 g of 2-(2,4-difluorophenyl)-1,2,3-propanetriol and thereto was added dropwise 9.05 g of valeryl chloride and stirred at room temperature for 6 hours. To the reaction mixture was added 30 mℓ of water and the resulting liquid was extracted with 100 mℓ of ethyl acetate. The organic layer was washed with saturated aqueous solution of sodium bicarbonate and further washed with water and with saturated aqueous solution of sodium chloride. The organic layer was dried over anhydrous sodium sulfate and the solvent was removed under reduced pressure. Thus obtained concentrate was purified by column chromatography on silica gel (hexane/ethyl acetate = 2/1) to give 3.16 g of the oily desired compound. 1 H-NMR (400MHz, CDCl 3 ) δppm: 7. 72-7. 64 (1H, m), 6. 95-6. 88 (1H, t), 6. 85-6. 78 (1H, m), 4. 52-4. 44 (4H, dd), 2. 40-2. 35 (2H, m), 2. 30-2. 25 (2H, m), 1. 66-1. 58 (2H, m) , 1. 55-1. 45 (2H, m) , 1. 43-1. 33 (2H, m) , 1. 30-1. 18 (2H, m) , 0. 96-0. 90 (3H, m) , 0. 88-0. 82 (3H, m) Preparation EXAMPLE 13 Synthesis of 1,3-di-n-butyryloxy-2-(2,4-difluorophenyl)-2-propanol (according to Reaction formula 2) In 30 mℓ of pyridine was dissolved 3.06 g of 2-(2, 4-difluorophenyl)-1,2,3-propanetriol and thereto was added dropwise 5.22 g of n-butyric anhydride and stirred at room temperature for 6 hours. To thus obtained reaction liquid was added 100 mℓ of ethyl acetate and the organic layer was separated. The organic layer was washed with 1N HCl, further washed with water and saturated aqueous solution of sodium chloride. After the organic layer was dried anhydrous sodium sulfate, the solvent was removed under reduced pressure. Thus obtained concentrate was purified by column chromatography on silica gel (hexane/ethyl acetate = 2/1) to give 5.12 g of the oily desired compound. 1 H-NMR (400MHz, CDCl 3 ) δppm: 7. 72-7. 65 (1H, m), 6. 95-6. 88 (1H, t), 6. 85-6. 76 (1H, m), 4. 55-4. 44 (4H, dd), 3. 82 (1H, s), 2. 28-2. 23 (4H, m) , 1. 6 0-1. 50 (4H, m) , 0. 8 8-0. 83 (6H, t) Preparation EXAMPLE 14 Synthesis of 1,3-diisobutyryloxy-2-(2,4-difluorophenyl)-2-propanol (according to Reaction formula 1) Under an atmosphere of argon, 5 mℓ of THF was slowly added to 925 mg of magnesium turnings, and then thereto was added dropwise 7 g of 2,4-difluorobromobenzene dissolved in 30 mℓ of THF with keeping the temperature at 20°C. After the reaction mixture was stirred for 1 hour with keeping the temperature at 20°C, 7.9 g of 1,3-diisobutyryloxyacetone dissolved in 10 mℓ of THF was added dropwise thereto with keeping the temperature at 0°C. After the dropping, the reaction mixture was stirred for 4 hours and then the reaction was stopped by adding 35 mℓ of IN sulfuric acid. The obtained liquid was extracted twice with 35 mℓ of ethyl acetate. The organic layer was washed with saturated aqueous solution with sodium bicarbonate and with saturated aqueous solution with sodium chloride, in turn. The solvent was removed under reduced pressure. Thus obtained concentrate was distilled under reduced pressure to give 10 g of the desired compound b. p. 114°-119°C/0. 5-0. 6mmHg 1 H-NMR (400MHz, CDCl 3 ) δppm: 7. 73-7. 65 (1H, m) , 6. 95-6. 88 (1H, t), 6. 85-6. 77 (1H, m) , 4. 54-4. 45 (4H, q) , 3. 90 (1H, s), 2. 55-2. 47 (2H, m) , 1. 10-1. 03 (12H, m) PreparationEXAMPLE 15 Synthesis of 1,3-diisobutyryloxy-2-phenyl-2-propanol (according to Reaction formula 1) Under an atmosphere of argon, 2 mℓ of diethyl ether was slowly added to 695 mg of magnesium turnings, and then thereto was added dropwise 4 g of bromobenzene dissolved in 10 mℓ of diethyl ether. The resulting liquid was stirred for 1 hour under refluxing and allowed to cool. That liquid was added dropwise to 50 mℓ of diethyl ether solution of 3.78 g of 1, 3-diisobutyryloxyacetone which was previously cooled to -50°C. After the resulting liquid was stirred at -50°C for 1 hour, a temperature thereof was gradually raised to room temperature. Then, the reaction mixture was added to 50 mℓ of 2 N aqueous solution of hydrochloric acid at 5°C or below, and an organic layer was separated and the aqueous layer was extracted twice with 50 mℓ of ethyl acetate. The organic layers were combined and washed three times with 1N aqueous solution of sodium hydroxide, washed twice with saturated aqueous solution with sodium chloride, and dried over anhydrous sodium sulfate. The solvent was removed under reduced pressure. The residue was purified by column chromatography on silica gel (eluent: n-hexane/ethyl acetate = 1/1) to give 5.5 g of the desired compound. 1 H-NMR (400MHz, CDCl 3 ) δppm: 7. 48-7. 46 (2H, m), 7. 39-7. 37 (2H, m) , 7. 35-7. 28 (1H, m), 4. 43-4. 35 (4H, q), 3. 15 (1H, s), 2. 56-2. 49 (2H, m) , 1. 11-1. 07 (12H, t) Preparation EXAMPLES 16 to 27 A diester shown in Table 3 was obtained by carrying out the same manner as described in Example 15 employing a compound shown in Table 3 instead of bromobenzene as a starting substance. A 1 H-NMR spectra of that ester was shown in Table 4. Prep. Ex. No. 1 H ― NMR (400MHz,CDCl 3 ) δ ppm 16 7.49-7.45 (2H,m),7.07-7.03 (2H,m),4.40-4.32 (4H,q),3.27 (1H,s),2.57-2.50 (2H,m),1.27-1.21 (12H,m) 17 7.44-7.33 (4H,dd),4.39-4.32 (4H,q),3.23 (1H,s), 2.56-2.50 (2H,m),1.11-1.08 (12H,m) 18 7.37-7.16 (4H,dd),4.40-4.33 (4H,q),3.12 (1H,s), 2.57-2.50 (2H,m),2.04 (3H,s),1.12-1.08 (12H,m) 19 7.61-7.54 (6H,m),7.45-7.42 (2H,m),7.37-7.35 (1H,m),4.47-4.38 (4H,q),3.26 (1H,s),2.56-2.51 (2H,m),1.12-1.09 (12H,m) 20 7.41-6.88 (4H,dd),4.40-4.32 (4H,q),3.81 (3H,s), 3.02 (1H,s),2.57-2.50 (2H,m),1.12-1.09 (12H,m) 21 7.41-7.36 (4H,m),4.43-4.33 (4H,m),3.02 (1H,s), 2.57-2.50 (2H,m),1.31 (9H,s),1.11-1.07 (12H,m) 22 7.85-7.82 (1H,d),7.37-7.35 (1H,d),7.32-7.24 (2H,m),4.75-4.68 (4H,q),4.20 (1H,s),2.52 -2.45 (2H,m),1.23 (2H,d),1.04-1.01 (10H,m) 23 7.44-7.42 (1H,d),7.21-7.15 (3H,m),4.55-4.48 (4H,q),3.34 (1H,s),2.57 (3H,s),2.55-2.48 (2H,m), 1.26-1.22 (2H,d),1.07-1.06 (10H,m) 24 7.81-7.79 (1H,d),7.39 (1H,d),7.29-7.27 (1H,m), 4.68 (4H,s),4.21 (lH,s),2.53 - 2.46 (2H,m), 1.06-1.03 (12H,m) 25 7.29-7.26 (1H,d),6.98-6.95 (2H,d),4.52-4.45 (4H,q),3.23 (1H,s),2.55-2.49 (2H,m),2.53 (3H,s), 2.28 (3H,s),1.10-1.07 (12H,m) 26 8.71 (1H,m),7.88-7.81 (1H,m),7.58-7.40 (5H,m), 4.81-4.67 (4H,m),3.43 (1H,s),2.55-2.48 (2H,m), 1.21-1.16 (2H,m),1.08-1.05 (10H,m) 27 7.98 (1H,d),7.86-7.81 (3H,m),7.58-7.56 (1H,d), 7.51-7.47 (2H,m),4.52-4.45 (4H,q),3.32 (1H,s), 2.55-2.48 (2H,m),1.23-1.21 (2H,m),1.09-1.06 (10H,m) EXAMPLE 28 (according to the invention) Synthesis of 2-(2,4-difluorophenyl)-3-acetoxy-1,2-propanediol Each test tube was charged with 10 mg of 2-(2,4-difluorophenyl)-1, 3-diacetoxy-2-propanol, each 10 mg of the enzymes shown in Table 1 (Enzyme Nos. 1 to 10), 1 mℓ of 50 mM acetate buffer (pH 5) and 1 mℓ of n-hexane. The each test tube was shaken at 30°C for 16 hours. Then, thereto was added 1 mℓ of ethyl acetate and the resulting liquid was extracted. The solvent was removed under reduced pressure to give an oily residue. The oily residue was dissolved in methanol and HPLC analysis was carried out to estimate a conversion ratio into the formed 2-(2,4-difluorophenyl)-3-acetoxy-1,2-propanediol and an optical purity thereof, and the results were shown in Table 5 (Conditions for carrying out the HPLC analysis/column: CHIRALPAK AD (0.46 X 25 cm), made by Daicel Chemical Industries, Ltd., eluent: n-hexane/ethanol = 9/1, detection wavelength: 254 nm, flow rate: 1 mℓ/min, temperature of the column: room temperature). Enzyme No. Conversion Ratio (%) Optical Purity (% ee) 1 34.3 (R) (-) 70.0 2 59.8 (R) (-) 75.0 3 96.2 (R) (-) 93.2 4 39.8 (R) (-) 90.7 5 55.8 (R) (-) 85.7 - 6 85.4 (R) (-) 91.8 7 44.0 (R) (-) 89.8 8 40.2 (R) (-) 71.3 9 42.8 (S) (+) 86.9 EXAMPLE 29 (according to the invention) Synthesis of (R)-2-(2,4-difluorophenyl)-3-acetoxy-1,2-propanediol A 10 ℓ reaction vessel was charged with 110 g of 2-(2,4-difluorophenyl)-1, 3-diacetoxy-2-propanol, 11 g of Lipase made by SEIKAGAKU CORPORATION, (derived from Rhizopus delemar , Enzyme No. 3), 2.8 ℓ of 50 mM acetate buffer (pH 5) and 2.8 ℓ of cyclohexane. The resulting mixture was stirred at 30°C for 47 hours. The obtained reaction mixture was extracted twice with 3 ℓ of ethyl acetate and the organic layers were combined and dried over anhydrous sodium sulfate. The solvent was removed under reduced pressure to give 90 g of (R)-2-(2,4-difluorophenyl)-3-acetoxy-1,2-propanediol. 1 H-NMR (400MHz, CDCl 3 ) δppm:7. 69-7. 65 (1H, m) , 6. 92 (1H, t, J=5. 37Hz), 6. 80 (1H, t, J=2. 93Hz), 4. 52 (2H, s), 3. 97 (1H, d, J=3. 42Hz), 3. 80 (1H, d, J=3. 42Hz), 3. 9 1 (1 H, s), 2. 0 0 (3H, s) IR ; ν cm -1 : 3420, 1711, 1501, 1240, 1055, 970, 847 [α] D 25 =-4.72° (c=1. 02, CH 3 OH) Optical purity : 98. 2%ee m. p. : 52° - 53°C EXAMPLE30 (according to the invention) Synthesis of 2-(2,4-difluorophenyl)-1,2,3-propanetriol A 2 ℓ reaction vessel was charged with 10 g of 2-(2,4-difluorophenyl)-1,3-diacetoxy-2-propanol, 2 g of Lipase AP-6 (made by Amano Pharmaceutical Co., Ltd., derived from Aspergillus niger , Enzyme No. 12), 500 mℓ of 50 mM phosphate buffer (pH 7.0) and 500 mℓ of cyclohexane. The resulting mixture was stirred at 30°C for 24 hours. The reaction liquid was extracted three times with 1000 mℓ of ethyl acetate and dried over anhydrous sodium sulfate. The solvent was removed under reduced pressure and the residue was purified by column chromatography on silica gel (n-hexane/ethyl acetate = 1/10) to give 6.6 g of 2-(2,4-difluorophenyl)-1,2,3-propanetriol. 1 H-NMR (400MHz, CDCl 3 ) δppm: 7. 73-7. 68 (1H, m) , 6. 92 (1H, t, J=8. 11Hz), 6. 79 (1H, t, J=2. 93Hz), 4. 13 (2H, d, J=12. 21Hz), 3. 80 (3H, t, J=11. 23Hz) IR ; ν cm -1 : 3382, 1622, 1503, 1123, 1071, 994, 968, 851 m. p. : 58° -59°C Preparation EXAMPLE 31 Synthesis of 2-(2,4-difluorophenyl)-1,2,3-propanetriol In a 200 mℓ reaction vessel, 10 g of 2-(2,4-difluorophenyl)-1,3-diacetoxy-2-propanol was dissolved in 30 mℓ of toluene and thereto was added 30 mℓ of 30 % aqueous KOH solution. The resulting liquid was stirred at room temperature for 24 hours and more. Then a toluene-layer and an aqueous layer were separated from each other and the aqueous layer was extracted twice with 50 mℓ of ethyl acetate. The organic layer was washed with brine and then dried over anhydrous sodium sulfate. The solvent was removed therefrom and the residue was purified in the same manner as in Example 30 to give 6.5 g of 2-(2,4-difluorophenyl)-1,2,3-propanetriol. EXAMPLE 32 (according to the invention) Synthesis of (S)-2-( 2, 4-difluorophenyl)-1-acetoxy-1,2-propanediol A 300 mℓ reaction vessel was charged with 5 g of 2-(2,4-difluorophenyl)-1, 2, 3-propanetriol, 100 mℓ of diisopropanol, 2.45 mℓ of acetic anhydride and 5 g of Novozym 435 made by NOVO NORDISK, Ltd. (derived from Candida antarctica , Enzyme No. 24). The resulting mixture was stirred at 30°C for 15 hours. After 10 mℓ of water was added thereto, the reaction liquid was filtered to remove the enzyme. An organic layer of the filtrate was dried over anhydrous sodium sulfate and the solvent was removed under reduced pressure. The residue was purified by column chromatography on silica gel (n-hexane/ethyl acetate = 1/1) to give 1 g of (S)-2-(2,4-difluorophenyl)-1-acetoxy-1,2-propanediol. The optical purity thereof was 8 % ee. EXAMPLE 33 (according to the invention) Each test tube was charged with 100 mg of 2-(2,4-difluorophenyl)-1,3-diisobutyryloxy-2-propanol, 10 mg of Lipase D (Enzyme No. 6), 0.9 mℓ of 50 mM acetate buffer (pH 5) and each 0.1 mℓ of the organic solvents shown in Table 6. The test tube was shaken at 30°C for 16 hours. Then, thereto was added 5 mℓ of ethyl acetate and the resulting liquid was extracted. The solvent was removed under reduced pressure to give an oily residue. The oily residue was dissolved in methanol and HPLC analysis was carried out. Each ratio of the formed (R)-2-(2,4-difluorophenyl)-3-isobutyryloxy-1,2-propanediol (mono ester), 2-(2,4-difluorophenyl)-1,2,3-propanetriol (triol) and the residual substrate (diester) and an optical purity of the formed monoester were shown in Table 6. (The conditions for carrying out the HPLC analysis/column: CHIRALPAK AD (0.46 mm X 25 cm) made by Daicel Chemical Industries, Ltd., eluent: n-hexane/ethanol = 9/1, detection wavelength : 254 nm, flow rate: 1.2 mℓ/min, temperature of the column: room temperature, elution time: 7.8 minutes (the diester), 12.3 minutes ((S) monoester), 17.4 minutes ((R) monoester) and 22.0 minutes (triol)). Added Organic Solvent Diester (%) Monoester (%) Monoester (% ee) Triol (%) Diisopropyl ether 50.07 48.83 90.89 1.10 n-Hexane 51.34 47.36 92.95 1.30 Cyclohexane 37.09 61.26 96.29 1.65 n-Heptane 45.27 53.09 94.77 1.64 n-Octane 42.17 56.43 87.89 1.41 n-Decane 45.17 53.36 91.15 1.47 Petroleum ether 46.44 52.47 90.57 1.09 Benzene 43.84 54.84 92.13 1.33 Toluene 49.10 49.58 91.21 1.33 Chloroform 48.02 50.19 92.09 1.78 Methylcyclohexane 45.06 53.86 94.90 1.08 Isooctane 47.87 51.09 94.64 1.04 None 52.46 46.57 89.13 0.97 EXAMPLE 34 (according to the invention) Each test tube was charged with 20 mg of 2-(2,4-difluorophenyl)-1,3-diisobutyryloxy-2-propanol, each 2 mg of the enzymes shown in Tables 1 and 2 and 1 mℓ of 50 mM acetate buffer (pH 5). The test tube was shaken at 30°C for 16 hours. Then, thereto was added 5 5 mℓ of ethyl acetate and the resulting liquid was extracted. The solvent was removed under reduced pressure to give an oily residue. The oily residue was dissolved in methanol and HPLC analysis was carried out in the same manner as in Example 33. Each ratio of the formed 2-(2,4-difluorophenyl)-3-isobutyryloxy-1,2-propanediol (monoester), 2-(2,4-difluorophenyl)-1,2,3-propanetriol (triol) and the residual substrate (diester) and an optical purity of the formed monoester were shown in Table 7. Enzyme No. Diester (%) Monoester (%) Monoester (% ee) Triol (%) 11 72.61 22.58 (R) 44.24 4.81 12 63.75 27.75 (R) 45.73 8.50 13 42.06 57.72 (R) 96.78 0.21 14 0.04 8.04 (R) 67.45 91.93 2 1.03 94.47 (R) 97.41 4.50 4 65.66 34.17 (R) 97.49 0.17 5 35.90 63.65 (R) 97.80 0.45 6 26.15 72.97 (R) 97.53 0.88 15 20.80 78.35 (R) 97.42 0.85 16 85.41 14.39 (R) 95.66 0.20 17 99.87 0.31 (S) 23.16 0 18 71.38 28.56 (R) 97.65 0.06 19 35.89 58.45 (R) 87.75 5.66 20 2.64 5.21 (R) 76.56 92.15 21 0 14.27 (R) 95.37 85.73 22 81.79 17.13 (S) 48.29 1.08 10 0.59 14.66 (R) 10.55 84.75 23 89.56 9.65 (S) 72.29 0.79 24 94.51 5.00 (S) 12.45 0.48 25 98.17 1.83 (R) 44.11 0 26 90.73 8.65 (S) 72.42 0.62 EXAMPLE 35 Synthesis of (R)-2-(2,4-difluorophenyl)-3-propionyloxy-1,2-propanediol A 200 mℓ reaction vessel was charged with 3 g of 2-(2,4-difluorophenyl)-1,3-dipropionyloxy-2-propanol, 200 mg of Lipase D made by Amano Pharmaceutical Co., Ltd. (derived from Rhizopus delemer , Enzyme No. 6), 100 mℓ of 50 mM acetate buffer (pH 5) and 10 mℓ of cyclohexane. The resulting mixture was stirred at 30°C to react for 18 hours. After the reaction liquid was extracted three times with 50 mℓ of ethylacetate, the organic layers were combined and the combined organic layer was washed with saturated aqueous solution with sodium bicarbonate and with saturated aqueous solution with sodium chloride and dried over anhydrous sodium sulfate. The solvent was removed under reduced pressure and the residue was purified by column chromatography on silica gel (eluent: n-hexane/ethyl acetate = 1/1) to give 1.55 g of oily (R)-2-(2,4-difluorophenyl)-3-propionyloxy-1,2-propanediol. An optical purity thereof was determined in the same manner as in Example 33. (Elution time: 16.7 minutes ((R)-form) and 13.5 minutes ((S)-form)). 1 H-NMR (400MHz, CDCl 3 ) δppm:7. 69-7. 63 (1H, m) , 6. 93-6. 89 (1H, m) , 6. 83-6. 77 (1H, m) , 4. 57-4. 50 (2H, q) , 3. 99-3. 96 (2H, d) , 3. 80-3. 77 (1H, d) , 2. 38 (1H, s), 2. 29-2. 22 (2H, m) , 1. 04-1. 00 (3H, t) [α] D 25 =-4. 4 0° (C=1. 011, CH 3 OH) Optical purity:84. 6% ee EXAMPLE 36 Synthesis of (R)-2-(2,4-difluorophenyl)-3-n-butyryloxy-1,2-propanediol A 200 mℓ reaction vessel was charged with 2 g of 2-(2,4-difluorophenyl)-1,3-di-n-butyryloxy-2-propanol, 100 mg of Lipase D made by Amano Pharmaceutical Co., Ltd. (derived from Rhizopus delemer , Enzyme No. 6) and 100 mℓ of 50 mM acetate buffer (pH 5). The resulting mixture was stirred at 30°C to react for 18 hours. After the reaction liquid was extracted three times with 50 mℓ of ethyl acetate, the organic layers were combined and the combined organic layer was washed with saturated aqueous solution with sodium bicarbonate and with saturated aqueous solution with sodium chloride and further dried over anhydrous sodium sulfate. The solvent was removed under reduced pressure and the residue was purified by column chromatography on silica gel (eluent: n-hexane/ethyl acetate = 3/2) to give 1.56 g of oily (R)-2-(2,4-difluorophenyl)-3-n-butyryloxy-1,2-propanediol. An optical purity thereof was determined in the same manner as Example 33. (Elution time: 16.6 minutes ((R)-form) and 12.9 minutes ((S)-form)). 1 H-NMR (400MHz, CDCl 3 ) δppm: 7. 67-7. 64 (1H, m) , 6. 92-6. 89 (1H, m) , 6. 82-6. 77 (1H, m) , 4. 58-4. 51 (2H, q) , 4. 0 2 (1H, s), 3. 98-3. 95 (1H, d) , 3. 79-3. 76 (1H, d), 2. 36 (1H, s), 2. 23-2. 19 (2H, m), 1. 54-1. 48 (2H, q), 0. 84-0. 81 (3H, t) [α] D 25 =-7 02° (C=0. 997, CH 3 OH) Optical purity:86. 4%ee EXAMPLE 37 Synthesis of (R)-2-(2,4-difluorophenyl)-3-n-pentanoyloxy-1,2-propanediol A 200 mℓ reaction vessel was charged with 2 g of 2-(2,4-difluorophenyl)-1,3-di-n-pentanoyloxy-2-propanol, 100 mg of Lipase D made by Amano Pharmaceutical Co., Ltd. (derived from Rhizopus delemer , Enzyme No. 6) and 100 mℓ of 50 mM acetate buffer (pH 5). The resulting mixture was stirred at 30°C to react for 18 hours. After the reaction liquid was extracted three times with 50 mℓ of ethyl acetate, the organic layers were combined and the combined organic layer was washed with saturated aqueous solution with sodium bicarbonate and with saturated aqueous solution with sodium chloride and further dried over anhydrous sodium sulfate. The solvent was removed under reduced pressure and the residue was purified by column chromatography on silica gel (eluent: n-hexane/ethyl acetate = 3/2) to give 1.01 g of oily (R)-2-(2,4-difluorophenyl)-3-n-pentanoyloxy-1,2-propanediol. An optical purity thereof was determined in the same manner as Example 33. (Elution time: 13.7 minutes ((R)-form) and 11.1 minutes ((S)-form)). 1 H-NMR (400MHz, CDCl 3 ) δppm: 7. 67-7. 64 (1H, m) , 6. 93-6. 89 (1H, m) , 6. 83-6. 77 (1H, m) , 4. 58-4. 51 (2H, q) , 4. 05 (1H, s), 3. 98-3. 95 (1H, d) , 3. 77-3. 76 (1H, d), 2. 35 (1H, s), 2. 25-2. 21 (2H, t), 1. 47-1. 43 (2H, t) , 1. 23-1. 19 (2H, q), 0. 85-0. 82 (3H, t) [α] D 25 =-6. 28° (C=0. 987, CH 3 OH) Optical Purity:92. 1%ee EXAMPLE 38 Synthesis of (R)-2(R)-2-(2,4-difluorophenyl)-3-isobutyryloxy-1, 2-propanediol A 200 mℓ reaction vessel was charged with 2 g of 2-(2,4-difluorophenyl)-1,3-diisobutyryloxy-2-propanol, 100 mg of Lipase D made by Amano Pharmaceutical Co., Ltd. (derived from Rhizopus delemer , Enzyme No. 6), 90 mℓ of 50 mM acetate buffer (pH 5) and 10 mℓ of cyclohexane. The resulting mixture was stirred at 30°C to react for 18 hours. After the reaction liquid was extracted three times with 50 mℓ of ethyl acetate, the organic layers were combined and the combined organic layer was washed with saturated aqueous solution with sodium bicarbonate and with saturated aqueous solution with sodium chloride and further dried over anhydrous sodium sulfate. The solvent was removed under reduced pressure and the residue was purified by means of column chromatography on silica gel (eluent: n-hexane/ethyl acetate = 3/2) to give 1.51 g of oily (R)-2-(2,4-difluorophenyl)-3-isobutyryloxy-1,2-propanediol. An optical purity thereof was determined in the same manner as Example 33. 1 H-NMR (400MHz, CDCl 3 ) δ ppm: 7. 69-7. 66 (1H, m) , 6. 91-6. 87 (1H, m) , 6. 78-6. 77 (1H, m), 4. 54-4. 45 (3H, m) , 3. 97-3. 78 (2H, dd), 2. 49-2. 42 (1H, m), 1. 01-0. 99 (6H, m) [α] D 25 =-7. 0 4° (C= 1. 00, CH 3 OH) Optical purity:96. 1% ee EXAMPLE 39 (according to the invention) Six 100 mℓ reaction vessels were prepared, each of which was charged with 5 g of 2-(2,4-difluorophenyl)-1,3-diisobutyryloxy-2-propanol, 45 mℓ of water, 5 mℓ of methylcyclohexane and 500 mg of Lipase D made by Amano Pharmaceutical Co., Ltd. (derived from Rhizopus delemer , Enzyme No. 6). Each temperature of the vessles was kept at 15°, 20°, 25° , 30° , 35 and 40°C, respectively. Each of the resulting mixture was adjusted to pH 5 by controlling with sodium hydroxide and allowed to react for 48 hours. After the reaction, each reaction mixture was extracted with ethyl acetate and each organic layer was washed with saturated aqueous solution with sodium hydrogencarbonate and with saturated aqueous solution with sodium chloride. The organic layer was dried over anhydrous sodium · sulfate and the solvent was removed under reduced pressure. The residue was dissolved in methanol and HPLC analysis was carried out in the same manner as in Example 33. Each ratio of the formed (R)-2-(2,4-difluorophenyl)-3-isobutyryloxy-1,2-propanediol (monoester), 2-(2,4-difluorophenyl)-1,2,3-propanetriol (triol) and the residual substrate (diester) and an optical purity of the formed monoester were shown in Table 8. Reaction temperature (°C) Diester (%) Monoester (%) Monoester (% ee) Triol (%) 15 8.75 87.37 98.23 3.88 20 7.35 85.41 97.32 7.24 25 7.30 86.80 97.67 5.90 30 11.39 82.91 95.26 5.71 35 12.86 82.36 94.53 4.78 40 35.01 62.06 86.49 2.94 EXAMPLE 40 (according to the invention) Three 100 mℓ reaction vessels were prepared, each of which was charged with 5 g of 2-(2,4-difluorophenyl)-1,3-diisobutyryloxy-2-propanol, 45 mℓ of water, 5 mℓ of methylcyclohexane and Lipase D made by Amano Pharmaceutical Co., Ltd. (derived from Rhizopus delemer , Enzyme No. 6). Each temperature of the vessels was kept at 6°, 10° and 15°C, respectively. Each of the resulting mixture was adjusted to pH 5.5 by controlling with sodium hydroxide and allowed to react for 48 hours. After the reaction, each reaction mixture was extracted with ethyl acetate and each organic layer was washed with saturated aqueous solution with sodium hydrogencarbonate and with saturated aqueous solution with sodim chloride. The organic layer was dried over anhydrous sodium sulfate and the solvent was removed under reduced pressure. The residue was dissolved in methanol and HPLC analysis was carried out in the same manner as in Example 35. Each ratio of the formed (R)-2-(2,4-difluorophenyl)-3-isobutyryloxy-1,2-propanediol (monoester), 2-(2,4-difluorophenyl)-1,2,3-propanetriol (triol) and the residual substrate (diester) and an optical purity of the formed monoester were shown in Table 9. Reaction temperature (°C) Diester (%) Monoester (%) Monoester (% ee) Triol (%) 6 17.59 80.25 96.72 2.16 10 6.35 89.84 97.26 3.61 15 4.94 89.32 97.27 5.74 Test EXAMPLE 41 Stability of monoester (acetoxy form) to pH Each test tube equipped with a closure was charged with 20 mg of (R)-2-(2,4-difluorophenyl)-3-acetoxy-1,2-propanediol (67.6 %ee) and 1 mℓ of 100 mM each kind of buffer having a pH of 4 to 9 was added thereto and each test tube was shaken at 30°C for 18 hours. Thereto was added 3 mℓ of ethyl acetate to extract and the solvent was removed under reduced pressure. The residue was dissolved in methanol and HPLC analysis was carried out in the same manner as in Example 33. An optical purity (R)-2-(2,4-difluorophenyl)-3-acetoxy-1,2-propanediol and a ratio of the formed 2-(2,4-difluorophenyl)-1,2,3-propanetriol (triol) were shown in Table 10. (Eluent time: 14.9 minutes ((S)-monoester), 16.5 minutes ((R)-monoester) and 22.0 minutes (triol). pH (Buffer) Monoester (% ee) Triol (%) pH 4 (Acetate Buffer) 65.0 0.28 pH 5 (Acetate Buffer) 61.8 0.22 pH 6 (Phosphate Buffer) 36.6 1.42 pH 7 (Phosphate Buffer) 1.2 12.1 pH 8 (Phosphate Buffer) 0.4 32.4 pH 9 (Phosphate Buffer) 1.6 9.8 Test EXAMPLE 42 Stability of monoester (isobutyryloxy form) to pH Each test tube equipped with a closure was charged with 20 mg of (R)-2-(2, 4-difluorophenyl)-3-isobutyryloxy-1, 2- propanediol (46.2 %ee) and 1 mℓ of 100 mM each kind of buffer having a pH of 4 to 9 was added thereto and each test tube was shaken at 30°C for 18 hours. Thereto was added 3 mℓ of ethyl acetate to extract and the solvent was removed under reduced pressure. The residue was dissolved in methanol and HPLC analysis was carried out in the same manner as in Example 33. An optical purity (R)-2-(2,4-difluorophenyl)-3-isobutyryloxy-1,2-propanediol (monoester) and a ratio of the formed 2-(2,4-difluorophenyl)-1,2,3-propanetriol (triol) were shown in Table 11. pH (Buffer) Monoester (% ee) Triol (%) pH 4 (Acetate Buffer) 46.0 N.D. pH 5 (Acetate Buffer) 45.4 N.D. pH 6 (Phosphate Buffer) 43.6 N.D. pH 7 (Phosphate Buffer) 21.4 0.17 pH 8 (Phosphate Buffer) 2.6 0.80 pH 9 (Phosphate Buffer) 0.6 1.38 EXAMPLE 43 (according to the invention) Synthesis of (-)-2-phenyl-1,3-isobutyryloxy-1, 2-propanediol A 100 mℓ reaction vessel was charged with 1 g of 2-phenyl-1,3-diisobutyryloxy-2-propanol, 100 mg of Lipase D made by Amano Pharmaceutical Co., Ltd. (derived from Rhizopus delemer , Enzyme No. 6), 45 mℓ of 50 mM acetate buffer (pH 5) and 5 mℓ of cyclohexane and the mixture was stirred at 30°C and allowed to react for 5 hours. After the resulting liquid was extracted three times with 50 mℓ of ethyl acetate, the organic layers were combined and washed with saturated aqueous solution with sodium hydrogencarbonate and with saturated aqueous solution with sodium chloride and dried over anhydrous sodium sulfate. The solvent was removed under reduced pressure and the residue was purified by column chromatography on silica gel (elution: n-hexane/ethyl acetate = 1/1) to give 0.17 g of oily (-)-2-phenyl-1,3-isobutyryloxy-1,2-propanediol. An optical purity thereof was determined in the same manner as in Example 33. (Elution time: 19.3 minutes ((+)-form) and 27.6 minutes ((-)-form)). 1 H-NMR (400MHz, CDCl 3 ) δppm: 7. 48-7. 46 (2H, m) , 7. 39-7. 37 (2H, m) , 7. 35-7. 28 (1H, m), 4. 51-4. 35 (2H, dd), 3. 83-3. 72 (2H, m) , 3. 38 (1H, s), 2. 56-2. 49 (1H, m) , 1. 71 (1H, s), 1. 09-1. 06 (6H, m) [ α ] D 25 =-13. 9 9° (C=1. 00, CH 3 OH) Optical Purity:93. 7% ee EXAMPLES 44 to 55 (according to the invention) The same procedure as in Example 43 was repeated except that as a starting substance of diester a compound shown in Table 12 was employing instead of 2-phenyl-1,3-diisobutyryloxy-2-propanol to give a corresponding monoester. Each of a yield, a specific rotation, an optical purity and 1 H-NMR of the resulting monoester were summarized in Tables 13 and 14, respectively. Starting Substance of Diester Ex. 44 2-(4-Fluorophenyl)-1,3-diisobutyryloxy-2-propanol Ex. 45 2-(4-Chlorophenyl)-1,3-diisobutyryloxy-2-propanol Ex. 46 2-(4-Methylphenyl)-1,3-diisobutyryloxy-2-propanol Ex. 47 2-(4-Methoxyphenyl)-1,3-diisobutyryloxy-2-propanol Ex. 48 2-(4-Biphenyl)-1,3-diisobutyryloxy-2-propanol Ex. 49 2-(4-t-Butylphenyl)-1,3-diisobutyryloxy-2-propanol Ex. 50 2-(2-Chlorophenyl)-1,3-diisobutyryloxy-2-propanol Ex. 51 2-(2-Methylphenyl)-1,3-diisobutyryloxy-2-propanol Ex 52 2-(2,4-Dichlorophenyl)-1,3-diisobutyryloxy-2-propanol Ex. 53 2-(2,4-Dimethylphenyl)-1,3-diisobutyryloxy-2-propanol Ex. 54 2-(1-Naphthyl)-1,3-diisobutyryloxy-2-propanol Ex. 55 2-(2-Naphthyl)-1,3-diisobutyryloxy-2-propanol Ex. No. Yield (g) Specific Rotation (CH 3 OH) Optical purity (%ee) Elution time of (+)-form/(-)-form (min.) 44 0.71 -10.6 (c=1.000) 95.3 21.5/23.2 45 0.68 -9.52 (c=0.987) 95.7 23.7/24.6 46 0.49 -0.49 (c=0.934) 93.8 21.4/31.2 47 0.52 -9.01 (c=0.976) 78.4 33.8/45.3 48 0.59 -7.46 (c=0.938) 91.1 49.2/42.6 49 0.55 -9.83 (c=0.935) 96.9 13.7/11.6 50 0.64 -8.87 (c=0.947) 80.0 12.4/22.1 51 0.16 -5.77 (c=0.970) 83.8 12.3/19.0 52 0.11 -8.60 (c=0.976) 75.4 12.9/15.5 53 0.063 -3.42 (c=0.934) 89.7 11.8/17.6 54 0.61 -12.8 (c=0.923) 58.0 25.2/21.8 55 0.66 -5.41 (c=0.924) 97.6 32.0/33.9 Ex. No. 1 H-NMR (400MHz,CDCl 3 ) δ ppm 44 7.47-7.42 (2H,m),7.08-7.03 (2H,m),4.48-4.33 (2H,dd), 3.80-3.68 (2H,m),3.47 (1H,s),2.56 - 2.49 (1H,m),1.78 (1H,s),1.09 -1.07 (6H,m) 45 7.43-7.33 (4H,dd),4.48-4.33 (2H,dd),3.79-3.67 (2H,m), 3.42 (1H,s),2.56 - 2.49 (1H,m),1.67 (1H,s),1.10 -1.08 (6H,m) 46 7.36-7.17 (4H,dd),4.48-4.32 (2H,dd),3.80-3.71 (2H,m), 3.31 (1H,s),2.56-2.49 (1H,m),2.34 (3H,s),1.75 (1H,s), 1.11-1.08 (6H,m) 47 7.40 - 6.88 (4H,dd),4.48-4.32 (2H,dd),3.81 (3H,s), 3.79-3.70 (2H,m),3.27 (1H,s),2.57 - 2.50 (1H,m),2.34 (1H,s),1.11 - 1.09 (6H,m) 48 7.62 - 7.53 (6H,m),7.46-7.42 (2H,m),7.37-7.34 (1H,m), 4.55-4.39 (2H,dd),3.87-3.77 (2H,m),3.37 (1H,s), 2.59-2.52 (1H,m),1.62 (1H,s),1.12 - 1.09 (6H,m) 49 7.39 (4H,m),4.51-4.33 (2H,dd),3.82-3.74 (2H,m), 3.23 (1H,s),2.57 - 2.50 (1H,m),2.25 (1H,s),1.31 (9H,s), 1.10-1.08 (6H,m) 50 7.81-7.79 (1H,m),7.36-7.34 (1H,m),7.37-7.23 (2H,m), 4.93-4.67 (2H,dd),4.46 (1H,s),4.21-3.94 (2H,dd), 2.45-2.36 (1H,m),0.96-0.88 (6H,m) 51 7.45-7.43 (1H,m),7.21-7.15 (3H,m),4.64-4.50 (2H,dd), 3.93-3.84 (2H,m),3.68 (1H,s),2.55 (3H,s),2.51-2.44 (1H,m), 1.04-0.99 (6H,m),2.45-2.36 (1H,m),0.96-0.88 (6H,m) 52 7.78-7.76 (1H,d),7.38 (1H,d),7.29-7.26 (1H,m),4.89-4.66 (2H,dd),4.48 (1H,s),4.18-4.09 (1H,m),3.92-3.04 (1H,m), 2.38-2.32 (1H,m),1.66 (1H,m),0.99 - 0.92 (6H,m) 53 7.32-7.30 (1H,d),6.99 - 6.97 (1H,d),4.61 - 4.47 (2H,dd), 3.90-3.84 (2H,m),2.55-2.46 (1H,m),2.51 (3H,s),2.29 (3H,s), 1.07-1.02 (6H,m) 54 8.67~8.65 (1H,d),7.88 - 7.81 (2H,m),7.61-7.59 (1H,m), 7.54 - 7.41 (3H,m),4.87 - 4.70 (2H,dd),4.16-4.09 (H,m), 3.70 (1H,s),2.52 - 2.47 (1H,m),1.58 (1H,s),1.28 - 1.24 (1H,m), 55 7.97-7.53 (1H,m),7.85 - 7.81 (2H,m),7.55 - 7.53 (1H,m), 7.50-7.46 (3H,m),4.59-4.45 (2H,dd),3.90-3.81 (2H,m),3.55 (1H,s),2.54 - 2.47 (1H,m),1.27 - 1.22 (1H,m),1.07 - 1.04 (5H,m) Preparation EXAMPLE 56 Synthesis of 1,3-dichloroacetoxy-2-(2,4-difluorophenyl)-2-propanol (according to Reaction formula 2) In 30 mℓ dichloromethane were dissolved 3.06 g of 2-(2,4-difluorophenyl)-1,2,3-propanetriol and 3.79 g of triethylamine and thereto was added dropwise 3.73 g of chloroacetyl chloride at a temperature of -10°C or below and after the dropping, allowed to react at room temperature for 4 hours. Into the reaction liquid were added 10 mℓ of water and 100 mℓ of ethyl acetate, and an organic layer was separated. The organic layer was washed with 1N hydrochloric acid, and further with water and with saturated aqueous solution with sodium chloride. After the organic layer was dried over anhydrous sodium sulfate, the solvent was removed under reduced pressure. Thus obtained concentrate was purified by column chromatography on silica gel (hexane/ethyl acetate = 2/1) to give 5.53 g of the oily desired compound. 1 H-NMR (400MHz, CDCl 3 ) δppm: 7. 71-7. 65 (1H, m) , 6. 97-6. 95 (1H, m) , 6. 93-6. 81 (1H, m), 4. 65-4. 55 (4H, dd), 4. 05 (4H, s), 3. 25 (1H, s)

Claims: A process for preparing an optically active 2-aryl-3-acyloxy-1,2-propanediol, which comprises allowing to act a microorganism or an enzyme having enzyme activity which allow to form an optically active 2-aryl-3-acyloxy-1,2-propanediol represented by the formula (VIII): wherein Ar is an aryl group which may be substituted, R is a normal chain or branched chain alkyl group, a normal chain or branched chain alkenyl group which may be substituted or an aryl group which may be substituted by stereospecific hydrolysis of an 2-aryl-1,3-diacyloxy-2-propanol represented by the formula (I): wherein each of Ar and R is the same as each of the defined above, on an 2-aryl-1,3-diacyloxy-2-propanol represented by the formula (I) and allowing to form an optically active 2-aryl-3-acyloxy-1,2-propanediol represented by the formula (VIII). The process of Claim 1 wherein Ar is 2,4-difluorophenyl group, R is a normal chain or branched chain alkyl group, or phenyl group. The process of Claim 2 wherein R is methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, isopropyl, isobutyl, chloromethyl, β-chloroethyl or γ-chloropropyl group. The process of Claim 1 wherein R is isopropyl group. The process of Claim 4 wherein Ar is phenyl, 4-fluorophenyl, 4-chlorophenyl, 4-methylphenyl, 4-methoxyphenyl, 4-biphenyl, 4-tert-butylphenyl, 2-chlorophenyl, 2-methylphenyl, 2,4-dichlorophenyl, 2,4-difluorophenyl, 2,4-dimethylphenyl, 1-naphthyl or 2-naphthyl group. The process of Claim 1, 2, 3, 4 or 5 wherein the microorganism or enzyme which hydrolyzes stereospecifically is a member selected from the group consisting of the microorganism belonging to Chromobacterium genus, Rhizopus genus, Mucor genus, Candida genus, Aspergillus genus, Geotrichum genus, Pseudomonas genus, Bacillus genus or Humicola genus, the enzyme derived from that microorganism and the enzyme derived from porcine pancreas. The process of Claim 1 wherein the stereospecific hydrolysis is carried out in the presence of an organic solvent. The process of Claim 7 wherein the organic solvent is a hydrocarbon. The process of Claim 1 wherein the stereospecific hydrolysis is carried out at 15°C or below. The process of Claim 1 wherein the stereospecific hydrolysis is carried out at pH 6 or below. A process for preparing an optically active 2-aryl-3-acyloxy-1,2-propanediol, which comprises allowing to act a microorganism or an enzyme having enzyme activity which esterifies only hydroxy group at 1-position or 3-position stereospecifically on a 2-aryl-1,2,3-propanetriol represented by the formula (III): wherein Ar is an aryl group which may be substituted in the presence of an acylating agent and allowing to form an optically active 2-aryl-3-acyloxy-1, 2-propanediol represented by the formula (VIII): wherein Ar is the same as defined above, R is a normal chain or branched chain alkyl group which may be substituted, a normal chain or branched chain alkenyl group which may be substituted or an aryl group which may be substituted. The process of Claim 11 wherein Ar is 2,4-difluorophenyl group, R is a normal chain or branched chain alkyl group, or phenyl group. The process of Claim 12 wherein R is methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, isopropyl, isobutyl, chloromethyl, β-chloroethyl or γ-chloropropyl group The process of Claim 11, 12 or 13 wherein the acylating agent is carboxylic acid, a carboxylic acid ester or a carboxylic acid anhydride. The process of Claim 11, 12, 13 or 14 wherein the microorganisms or enzyme which esterifies stereospecifically is a member selected from the group consisting of the microorganism belonging to Chromobacterium genus, Rhizopus genus, Mucor genus, Candida genus, Aspergillus genus, Geotrichum genus, Pseudomonas genus, Bacillus genus or Humicola genus, the enzyme derived from that microorganism, the enzyme derived from porcine pancreas and the enzyme derived from wheat.

Inventors: HASEGAWA JUNZO, KAWANO SHIGERU, KIZAKI NORIYUKI, MIYAMOTO KENJI, YASOHARA YOSHIHIKO, HASEGAWA, JUNZO, KAWANO, SHIGERU, KIZAKI, NORIYUKI, MIYAMOTO, KENJI, YASOHARA, YOSHIHIKO
Applicants: KANEGAFUCHI CHEMICAL IND, KANEGAFUCHI KAGAKU KOGYO KABUSHIKI KAISHA
Application year: 1995
Main classification: C07C33
IPC codes: C07C69, C07C33, C07C309, C07D303, C07D521, C12P7, C12P41