METHOD FOR ISOMERIZATION A GLYCIDATE DERIVATIVE

Abstract: A catalyst for isomerization consisting essentially of a salt or complex salt represented by the formula: [ML m ] n+ [Y] (I) where M is a metal of Group IB, IIA, IIB or VIII of the periodic table, L is a ligand, Y is a conjugated base of a Bronsted acid, m is 0, 1, 2, 3 or 4 and n is 1, 2 or 3.

Description: The present invention relates to a method for isomerizing a glycidate in the presence of a catalyst. There have been several reports on reagents for isomerizing glycidates. As reaction reagents for isomerization useful for the production of pyruvic acid derivatives, there have been known (a) an acid mixture of a lower fatty acid and a mineral acid such as hydrochloric acid or sulfuric acid (JP-B- 35069/1978 and JP-A- 149970/1978), and (b) a Lewis acid such as boron trifluoride or aluminum chloride, or a proton acid such as sulfuric acid or p-toluenesulfonic acid (JP-A-99445/1981). However, the method of using the reagent (a) has a drawback that substantial amounts of aldehydes are likely to be produced as by-products due to decarboxylation, and the yield of the reaction is low. Whereas, the method of using the reagent (b) has a drawback that only corrosive sulfuric acid is practically useful as a catalyst, and in order to obtain a satisfactory yield with other members of the reagent, such members are required to be used in an amount at least equimolar to the substrate. As reagents for isomerizing glycidates to 2-hydroxy-3-butenoates, there have been known (c) a proton acid such as sulfuric acid or hydrochloric acid (JP-B- 19093/1982), (d) a strongly acidic cation exchange resin (JP-B- 8669/1979), and (e) a Lewis acid such as boron trifluoride, aluminum chloride or magnesium chloride (JP-B- 19092/1982 and JP-A- 22613/1980). However, the method of using the reagent (c) has a drawback that an extraction operation is required for the separation of the proton acid used and the resulting product, and in certain cases, a silica gel column must be used for purification, whereby the yield is low. The method of using the reagent (d) has a drawback that an expensive ion exchange resin must be used in a great amount. In the case of the reagent (e), it is necessary to use a great amount of a Lewis acid in a special solvent, and the yield in the isomerization reaction is not good. As catalyst for the production of phenylacetaldehyde by the isomerization of styrene oxide, there has been known an alkaline earth metal sulfonate (JP-A- 106 933/1975). However, the method has difficulties in the economical feasibility and the stability of the resulting phenylacetaldehyde as the reaction is conducted at a high temperature of at least 200 o C. As catalyst for the isomerization reaction form quadricyclanes to norbornadienes there has been known a cyclopropenylidene palladium complex (earlier EP-A-0 118 801). B-A-2 052 293 discloses a process and catalyst for preparing unsaturated aliphatic esters from aliphatic dienes. The present inventors have conducted extensive researches with an aim to overcome the above-mentioned drawbacks inherent to the conventional methods, and as a result, have found an active catalyst which is capable of isomerizing a glycidate in good yield. The present invention has been accomplished based on these discoveries. Namely, the present invention provides a method for isomerizing a glycidate derivative, in the presence of a salt or complex salt represented by the formula: where M is a metal selected from the group consisting of copper, silver, magnesium, barium, calcium, zinc, cadmium, mercury, iron, cobalt, nickel, rhodium, palladium, iridium and platinum, L is a ligand or a mixture of ligands, Y is a perhalogenoate or a sulfonate, m is 0, 1, 2, 3 or 4, and n is 1, 2 or 3 at temperatures in the range of from 40 to 160°C as identified below. In the above formulas, Ar is an aryl group, R¹ is a hydrogen atom or a methyl group, R² is a lower alkyl group, each of R³, R⁴, R⁵ and R⁶ is a hydrogen atom, an alkyl group, an aralkyl group or an aryl group, or R³ and R⁴, R³ and R⁶, R⁴ and R⁵ or R⁴ and R⁶ may together form a polymethylene group. Now, the present invention will be described in detail with reference to the preferred embodiments. The salt or complex salt of the formula I of the present invention may be available as a commercial product, or may readily be prepared. As the metal represented by M in the formula I, there may be mentioned, for example, copper, silver, magnesium, barium, calcium, zinc, cadmium, mercury, iron, cobalt, nickel, rhodium, palladium, iridium or platinum. As the ligand represented by L, there may be mentioned, for example, a π-allyl group, a π-crotyl group, a π-methallyl group, a cyclopentadienyl group, an acetylacetonate group, a 8-methoxy-4-cycloocten-1-yl group, 1,5-cyclooctadiene, cyclooctatetraene, norbornadiene, dicyclopentadiene, benzene, pyridine or bipyridine, triphenylphosphine, triethylphosphine, tri-n-butylphosphine, tricyclohexylphosphine, triphenylphosphite, trimethylphosphite, triethylphosphite or tri-n-butylphosphite. As the conjugated base of a Brønsted acid represented by Y, there may be mentioned a perhalogenoate such as a perchlorate or a periodate, or an conjugated base of an oxoacid such as a sulfonate, e.g. a trifluoromethanesulfonate, a fluorosulfonate, a trifluoromethylbenzenesulfonate or a methanesulfonate. More specifically, the salt or complex salt of the formula I includes allyl(1,5-cyclooctadiene) palladium trifluoromethanesulfonate, allyl(1,5-cyclooctadiene) palladium perchlorate, allyl(1,5-cyclooctadiene) palladium p-trifluoromethylbenzenesulfonate, allyl(norbornadiene) palladium trifluoromethanesulfonate, allyl(norbornadiene) palladium perchlorate, allyl(norbornadiene) palladium p-trifluoromethylbenzenesulfonate, allyl(dicyclopentadiene) palladium trifluoromethanesulfonate, crotyl(1,5-cyclooctadiene) palladium trifluoromethanesulfonate, 8-methoxy-4-cyclocten-1-yl(1,5-cyclooctadiene) palladium trifluoromethanesulfonate, 8-methoxy-4-cycloocten-1-yl(1,5-cyclooctadiene) palladium perchlorate, acetylacetonate(1,5-cyclooctadiene) palladium trifluoromethanesulfonate, acetylacetonate(norbornadiene) palladium trifluoromethanesulfonate, allyl bis(triphenylphosphine) palladium trifluoromethanesulfonate, allyl bis(triethylphosphine) palladium perchlorate, allyl bis(triethylphosphine) palladium trifluoromethanesulfonate, allyl bis(tri-n-butylphosphine) palladium perchlorate, allyl bis(tri-n-butylphosphine) palladium trifluoromethanesulfonate, allyl bis(triphenylphosphite) palladium perchlorate, allyl bis(triphenylphosphite) palladium trifluoromethanesulfonate, allyl bis(tri-ethylphosphite) palladium perchlorate, allyl bis(triethylphosphite) palladium trifluoromethanesulfonate, methallyl bis(triphenylphosphite) palladium perchlorate, 1,5-cyclooctadiene rhodium trifluoromethanesulfonate, norbornadiene rhodium trifluoromethanesulfonate, bis(1,5-cyclooctadiene) rhodium perchlorate, 1,5-cyclooctadiene(norbornadiene) rhodium trifluoromethanesulfonate, norbornadiene(1,5-cyclooctadiene) rhodium perchlorate, (1,5-cyclooctadiene)bis(triphenylphosphine) rhodium trifluoromethanesulfonate, (norbornadiene)bis(triphenylphosphine) rhodium perchlorate, (1,5-cyclooctadiene)bis(triphenylphosphite) rhodium perchlorate, (1,5-cyclooctadiene)bis(triphenylphosphite) rhodium trifluoromethanesulfonate, (1,5-cyclooctadiene)bis(triethylphosphite) rhodium trifluoromethanesulfonate, (1,5-cyclooctadiene)bis(triethylphosphite) rhodium perchlorate, bis(cyclopentadienyl) cobalt perchlorate, cyclopentadienyl(1,5-cyclooctadiene) nickel trifluoromethanesulfonate, nickel perchlorate, bipyridine(1,5-cyclooctadiene) iridium trifluoromethanesulfonate, 2,5-cyclopentadionate(1,5-cyclooctadiene) platinum trifluoromethanesulfonate, bis(bipyridine) platinum perchlorate, iron perchlorate, silver perchlorate, silver trifluoromethanesulfonate, silver p-trifluoromethylbenzenesulfonate, magnesium perchlorate, zinc perchlorate, barium perchlorate, calcium perchlorate, cadmium perchlorate and mercury perchlorate. Further, as the conjugated base of a Brønsted acid represented by Y in the formula I, there may be employed a fluorinated polymer having a sulfonate as its side chain. Now, the isomerization reactions wherein the salt or complex salt of the formula I is used, will be described. (A) Production of an arylpyruvate by the isomerization of an arylglycidate where Ar is an aryl group, R¹ is a hydrogen atom or a methyl group, and R² is a lower alkyl group. As the arylglycidate represented by the formula II to be used in the above isomerization, there may be employed methyl esters of arylglycidic acids such as methyl 3-phenylglycidate, methyl 3-(4-methylphenyl)glycidate, methyl 3-(4-ethylphenyl)glycidate, methyl 3-(4-isopropylphenyl)glycidate, methyl 3-(4-t-butylphenyl)glycidate, methyl 3-(4-cyclohexylphenyl)glycidate, methyl 3-(3,4-dimethylphenyl)glycidate, methyl 3-(2,5-dimethylphenyl)glycidate, methyl 3-(4-fluorophenyl)glycidate, methyl 3-(4-chlorophenyl)glycidate, methyl 3-(4-bromophenyl)glycidate, methyl 3-(2-chlorophenyl)glycidate, methyl 3-(3-chlorophenyl)glycidate, methyl 3-(pentafluorophenyl)glycidate, methyl 3-(4-nitrophenyl)glycidate, methyl 3-(3-nitrophenyl)glycidate, methyl 3-(2-nitrophenyl)glycidate, methyl 3-(4-dimethylaminophenyl)glycidate, methyl 3-(2-methoxyphenyl)glycidate, methyl 3-(3-methoxyphenyl)glycidate, methyl 3-(4-methoxyphenyl)glycidate, methyl 3-(3,4-dimethoxyphenyl)glycidate, methyl 3-(4-benzyloxyphenyl)glycidate, methyl 3-(3-benzyloxyphenyl)glycidate, methyl 3-(4-methoxycarbonylphenyl)glycidate, methyl 3-(1-naphthyl)glycidate, methyl 3-(2-naphthyl)glycidate, and methyl 3-[4-(1-oxo-2-isoindolinyl)phenyl]glycidate, and lower alkyl esters such as ethyl esters, isopropyl esters or t-butyl esters of such acids. Further, as a glycidate with the ß-position substituted by two substituents, there may be employed methyl esters of glycidic acids having an aromatic substituent, such as methyl 3-methyl-3-phenylglycidate, methyl 3-methyl-3-(4-methylphenyl)glycidate, methyl 3-methyl-3-(3-methylphenyl)glycidate, methyl 3-methyl-3-(2-methylphenyl)glycidate, methyl 3-methyl-3-(4-ethylphenyl)glycidate, methyl 3-methyl-3-(4-isopropylphenyl)glycidate, methyl 3-methyl-3-(4-isobutylphenyl)glycidate, methyl 3-methyl-3-(4-t-butylphenyl)glycidate, methyl 3-methyl-3-(4-cyclohexylphenyl)glycidate, methyl 3-methyl-3-(4-chlorophenyl)glycidate, methyl 3-methyl-3-(4-fluorophenyl)glycidate, methyl 3-methyl-3-(4-methoxyphenyl)glycidate, methyl 3-methyl-3-(4-acetoxyphenyl)glycidate, methyl 3-methyl-3-(3,4-dimethylphenyl)glycidate, methyl 3-methyl-3-(2,5-dimethylphenyl)glycidate, methyl 3-methyl-3-[4-(4'-fluorophenyl)phenyl]glycidate, methyl 3-methyl-3-(4-benzyloxyphenyl)glycidate, methyl 3-methyl-3-(3-benzyloxyphenyl)glycidate, methyl 3-methyl-3-(4-phenoxyphenyl)glycidate, methyl 3-methyl-3-(3-phenoxyphenyl)glycidate, methyl 3-methyl-3-[4-(1-oxo-2-isoindolinyl)phenyl]glycidate, methyl 3-methyl-3-(4-dimethylaminophenyl)glycidate, methyl 3-methyl-3-(2-methylphenyl)glycidate, methyl 3-methyl-3-(4-methoxycarbonylphenyl)glycidate, methyl 3-methyl-3-naphthylglycidate and methyl 3-methyl-3-indolinylglycidate, and lower alkyl esters such as ethyl esters, isopropyl esters or t-butyl esters of such acids. Such a substituted glycidate represented by the formula II is a compound which is readily obtainable by a so-called Darzens' reaction from a carbonyl compound and a 2-haloacetate. Further, this compound may also be produced by an epoxidation reaction of an α,β-unsaturated carboxylate. For the isomerization reaction, the catalyst for isomerization represented by the formula I may be used within a range of from 0.01 to 10 mol % relative to the arylglycidate of the formula II as the starting material. However, from the viewpoints of the economy and the catalytic activity, it is preferred to use the catalyst in an amount within a range of from 0.1 to 1.0 mol %. The method of the present invention may be conducted without using a solvent. However, it is possible to use a solvent which does not affect the reaction, for example, an aromatic hydrocarbon solvent such as benzene, toluene or xylene, a halogenated solvent such as chloroform or methylene chloride, a ketone solvent such as acetone, methyl ethyl ketone or diethyl ketone, or other solvents such as ethyl acetate, dimethylsulfoxide, dimethylformamide or diisopropyl ether. The reaction proceeds smoothly within a range of from room temperature to 200 o C. However, from the viewpoints of e.g. the efficiency of the reaction and the selectivity, it is preferred to conduct the reaction at a temperature of from 40 to 160 o C. Among the arylpyruvates obtainable by the isomerization of the present invention, e.g. phenylpyruvate is known to be a compound which can readily be converted to phenylalanine as a starting material for a methyl ester of L-aspartyl-L-phenylalanine which is useful as a sweetner. Further, a 3-methyl-2-ketocarboxylate obtainable by the above-mentioned isomerization can readily be led, by treatment with a suitable oxidizing agent, to a 2-aryl propionic acid derivative useful as an anti-inflammatory drug. (B) Production of a 2-hydroxy-3-alkenoate by the isomerization of a glycidate where each of R³, R⁴, R⁵ and R⁶ is a hydrogen atom, an alkyl group, an aralkyl group or an aryl group, or R³ and R⁴, R³ and R⁶, R⁴ and R⁵ or R⁴ and R⁶ may together form a polymethylene group, and R² is a lower alkyl group. The glycidate represented by the formula IV to be used for the above isomerization, there may be employed methyl esters of glycidic acids having an aromatic substituent, such as methyl 3-methyl-3-phenylglycidate, methyl 3-ethyl-3-phenylglycidate, methyl 3-isopropyl-3-phenylglycidate, methyl 3-isobutyl-3-phenylglycidate, methyl 3-hexyl-3-phenylglycidate, methyl 3-octyl-3-phenylglycidate, methyl 3-methoxymethyl-3-phenylglycidate, methyl 3-methyl-3-(4-methylphenyl)glycidate, methyl 3-methyl-3-(3-methylphenyl)glycidate, methyl 3-methyl-3-(2-methylphenyl)glycidate, methyl 3-methyl-3-(4-ethylphenyl)glycidate, methyl 3-methyl-3-(4-isopropylphenyl)glycidate, methyl 3-methyl-3-(4-isobutylphenyl)glycidate, methyl 3-methyl-3-(4-t-butylphenyl)glycidate, methyl 3-methyl-3-(4-cyclohexylphenyl)glycidate, methyl 3-methyl-3-(4-chlorophenyl)glycidate, methyl 3-methyl-3-(4-fluorophenyl)glycidate, methyl 3-methyl-3-(4-methoxyphenyl)glycidate, methyl 3-methyl-3-(4-acetoxyphenyl)glycidate, methyl 3-methyl-3-(3,4-dimethylphenyl)glycidate, methyl 3-methyl-3-(2,5-dimethylphenyl)glycidate, methyl 3-methyl-3-[4-(4'-fluorophenyl)phenyl]glycidate, methyl 3-methyl-3-(4-benzyloxyphenyl)glycidate, methyl 3-methyl-3-(3-benzyloxyphenyl)glycidate, methyl 3-methyl-3-(4-phenoxyphenyl)glycidate, methyl 3-methyl-3-(3-phenoxyphenyl)glycidate, methyl 3-methyl-3-[4-(1-oxo-2-isoindolinyl)phenyl]glycidate, methyl 3-methyl-3-(4-dimethylaminophenyl)glycidate, methyl 3-methyl-3-(2-methylphenyl)glycidate, methyl 3-methyl-3-(4-methoxycarbonylphenyl)glycidate, methyl 3-ethyl-3-(4-methylphenyl)glycidate, methyl 3-ethyl-3-(4-fluorophenyl)glycidate, methyl 3-ethyl-3-(4-methoxycarbonylphenyl)glycidate, methyl 3-isopropyl-3-(4-methylphenyl)glycidate, methyl 3-isopropyl-3-(4-chlorophenyl)glycidate, methyl 3-butyl-3-(4-methylphenyl)glycidate, methyl 3-methyl-3-naphthylglycidate, methyl 3-methyl-3-indolinylglycidate, methyl 2,3-dimethyl-3-phenylglycidate, methyl 2,3-diethyl-3-phenylglycidate, methyl 2-methyl-3-ethyl-3-phenylglycidate, methyl 2-ethyl-3-methyl-3-(4-methylphenyl)glycidate, methyl 2-phenyl-3-methyl-3-phenylglycidate, methyl 2-octyl-3-methyl-3-phenylglycidate, methyl 2-methyl-3-octyl-3-phenylglycidate and methyl 3-benzylglycidate, or ethyl esters, isopropyl esters, or t-butyl esters of such acids. Further, as a glycidate having an alkyl substituent, there may be employed methyl esters of glycidic acids such as methyl 3-methylglycidate, methyl 3-ethylglycidate, methyl 3-isopropylglycidate, methyl 3-octylglycidate, methyl 3-cyclohexylglycidate, methyl 3-methoxymethylglycidate, methyl 3,3-dimethylglycidate, methyl 3,3-diethylglycidate, methyl 3-methyl-3-ethylglycidate, methyl 3-methyl-3-isopropylglycidate, methyl 3-methyl-3-butylglycidate, methyl 3-methyl-3-octylglycidate, methyl 3-methoxymethyl-3-methylglycidate, methyl 3-acetoxymethyl-3-methylglycidate, methyl 2,3-dimethylglycidate, methyl 2-methyl-3-ethylglycidate, methyl 2,3-epoxycyclohexylidene acetate, methyl 2,3-epoxycyclopentylidene acetate, methyl 2,3-epoxycyclododecylidene acetate, methyl 2-methyl-2,3-epoxycyclohexylidene acetate, methyl 2-methyl-2,3-epoxycyclopentylidene acetate, methyl 2-(4-fluorophenyl)-2,3-epoxycyclohexylidene acetate, methyl 2-phenyl-2,3-epoxycyclohexylidene acetate, methyl 3,3-dimethyl-2-phenylglycidate, methyl 3,3-diethyl-2-phenylglycidate, 1-methoxycarbonyl-1-cyclohexeneoxide and 1-methoxycarbonyl-2-methyl-1-cyclohexeneoxide, and lower alkyl esters of the above glycidic acids, such as the ethyl esters, isopropyl esters or t-butyl esters. The above-mentioned substituted glycidate represented by the formula IV is a compound which is readily obtainable by a so-called Darzens' reaction from a carbonyl compound and a 2-halocarboxylate. Further, this compound may also be prepared by e.g. the epoxidation reaction of an α,β-unsaturated carboxylate. In the practical operation of the isomerization, the catalyst for isomerization represented by the formula I is used in an amount within a range of from 0.001 to 10 mol % relative to the substituted glycidate of the formula IV as the starting material. The method of the present invention may be conducted without using a solvent. However, it is possible to use a solvent which does not affect the reaction, for instance, an aromatic hydrocarbon solvent such as benzene, toluene or xylene, a halogenated solvent such as methylene chloride, chloroform or carbon tetrachloride, an ether solvent such as diethyl ether, diisopropyl ether or dimethoxy ethane, an aliphatic hydrocarbon solvent such as pentane or hexane, an ester or ketone solvent such as ethyl acetate, acetone, methyl ethyl ketone or methyl isopropyl ketone, or other solvent such as dimethylsulfoxide or dimethylformamide. The reaction may be conducted at a temperature or from room temperature to 160 o C. In the case where a glycidate of the formula IV where R³ is an aryl group and each of R⁴, R⁵ and R⁶ is a hydrogen atom, is employed, compounds other than the desired compound (3-methylpyruvate) are likely to form as by-products at a high temperature. Accordingly, for the production of a 2-hydroxy-3-alkenoate, it is preferred, from the viewpoint of the selectivity of the reaction, to choose a temperature range from room temperature to 100 o C. Among 2-hydroxy carboxylic acid derivatives obtainable by the reaction of the present invention, 3-(substituted aryl)alkenoates can be further isomerized to obtain substituted arylpyruvates. They may be converted by the treatment with a suitable oxidizing agent, to 2-(substituted aryl)propionic acid compounds useful as anti-inflammatory drugs (see Reference Example given hereinafter). Further, among 2-hydroxy carboxylate derivatives represented by the formula V in the present reaction, e.g. isopropenyl lactate can be converted to isopropenyl lactic acid, which is useful as a monomer for the copolymerization with e.g. acrylic acid (DE-B- 2646803), and also useful as a starting material for an oxazolidine dione derivative having an insecticidal activity (DE-B- 2207576). EXAMPLE 1 Methyl 3-phenylglycidate (1.78 g, 10 mmol), allyl (1,5-cyclooctadiene) palladium trifluoromethanesulfonate (40 mg, 0.10 mmol) as a catalyst and benzene (10 ml) as a solvent, were introduced into a 25 ml egg plant type flask and stirred at 60 o C for 1 hour. After the completion of the reaction, the reaction mixture was cooled to room temperature, and the solvent was distilled off under reduced pressure. Hexane (about 15 ml) and ether (about 5 ml) were added to the residue, and the precipitates were filtered and washed with hexane. From the filtrate and washing solution, the solvent was distilled off under reduced pressure, whereby colorless oily substance (1.75 g) was obtained. From the nuclear magnetic resonance spectrum and the infrared absorption spectrum, this substance was confirmed to be substantially pure methyl 3-phenylpyruvate. The results are shown in the following table. (Example 1) Starting material: 1.78 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 40 mg (0.10 mmol) Solvent: Benzene (10 ml) Reaction temp.: 60 o C Reaction time: 1 hr. Yield: 98% EXAMPLES 2 and 3 In the same manner as in Example 1, methyl 3-phenylpyruvate was obtained from methyl 3-phenylglycidate. The results are shown in the following tables. (Example 2) Starting material: 0.89 g (5.0 mmol) Catalyst: [Rh(COD)₂][Tf], 100 mg (0.20 mmol) Solvent: Benzene (10 ml) Reaction temp.: 80 o C Reaction time: 2 hrs. Yield: 98% (Example 3) Starting material: 1.78 g (10 mmol) Catalyst: [(NBD)Rh(COD)][ClO₄], 8.0 mg (0.02 mmol) Solvent: Benzene (10 ml) Reaction temp.: 80 o C Reaction time: 2 hrs. Yield: 98% EXAMPLES 4 and 5 In the same manner as in Example 1, ethyl 3-phenylpyruvate was obtained from ethyl 3-phenylglycidate. The results are shown in the following tables. (Example 4) Starting material: 1.92 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 40 mg (0.10 mmol) Solvent: Benzene (5 ml) Reaction temp.: 60 o C Reaction time: 1 hr. Yield: 100% (Example 5) Starting material: 1.92 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][ClO₄], 36 mg (0.10 mmol) Solvent: Benzene (10 ml) Reaction temp.: 60 o C Reaction time: 1 hr. Yield: 95% EXAMPLES 6 to 8 In the same manner as in Example 1, methyl 3-(4-methylphenyl)pyruvate was obtained from methyl 3-(4-methylphenyl)glycidate. The results are shown in the following tables. (Example 6) Starting material: 2.19 g (11 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 40 mg (0.10 mmol) Solvent: Benzene (5 ml) Reaction temp.: 70 o C Reaction time: 2 hrs. Yield: 96% (Example 7) Starting material: 1.92 g (10 mmol) Catalyst: [(MeO-C₈H₁₂)Pd(COD)][Tf], 5.0 mg (0.01 mmol) Solvent: Methylene chloride (10 ml) Reaction temp.. 50 o C Reaction time: 1 hr. Yield: 100% (Example 8) Starting material: 0.50 g (2.6 mmol) Catalyst: [Ag][Tf], 2.0 mg (0.01 mmol) Solvent: Benzene (10 ml) Reaction temp.: Room temperature Reaction time: 2 hrs. Yield: 100% EXAMPLES 9 and 10 In the same manner as in Example 1, methyl 3-(4-ethylphenyl)pyruvate was obtained from methyl 3-(4-ethylphenyl)glycidate. The results are shown in the following tables. (Example 9) Starting material: 2.06 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 40 mg (0.10 mmol) Solvent: Benzene (5 ml) Reaction temp.: 70 o C Reaction time: 2 hrs. Yield: 99% (Example 10) Starting material: 2.06 g (10 mmol) Catalyst: [(MeO-C₈H₁₂)Pd(COD)][Tf], 30 mg (0.07 mmol) Solvent: Benzene (10 ml) Reaction temp.: 80 o C Reaction time: 2 hrs. Yield: 95% EXAMPLES 11 and 12 In the same manner as in Example 1, methyl 3-(4-isopropylphenyl)pyruvate was obtained from methyl 3-(4-isopropylphenyl)glycidate. The results are shown in the following tables. (Example 11) Starting material: 2.20 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 40 mg (0.10 mmol) Solvent: Benzene (5 ml) Reaction temp.: 70 o C Reaction time: 1 hr. Yield: 99% (Example 12) Starting material: 2.20 g (10 mmol) Catalyst: [(MeO-C₈H₁₂)Pd(COD)][Tf], 5.0 mg (0.01 mmol) Solvent: Methylene chloride (10 ml) Reaction temp.: 50 o C Reaction time: 2 hrs. Yield: 95% EXAMPLES 13 to 16 In the same manner as in Example 1, methyl 3-(4-fluorophenyl)pyruvate was obtained from methyl 3-(4-fluorophenyl)glycidate. The results are shown in the following tables. (Example 13) Starting material: 8.0 g (40 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 130 mg (0.32 mmol) Solvent: Benzene (30 ml) Reaction temp.: 60 o C Reaction time: 2 hrs. Yield: 100% (Example 14) Starting material: 1.96 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 40 mg (0.10 mmol) Solvent: Benzene (10 ml) Reaction temp.: 60 o C Reaction time: 1 hr. Yield: 99% (Example 15) Starting material: 2.00 g (10 mmol) Catalyst: [(MeO-C₈H₁₂)Pd(COD)][Tf], 5.0 mg (0.01 mmol) Solvent: Methylene chloride (10 ml) Reaction temp.: 50 o C Reaction time: 2 hrs. Yield: 98% (Example 16) Starting material: 2.00 g (10 mmol) Catalyst: [Rh(COD)₂][Tf], 20 mg (0.04 mmol) Solvent: Benzene (10 ml) Reaction temp.: 80 o C Reaction time: 2 hrs. Yield: 100% EXAMPLES 17 and 18 In the same manner as in Example 1, methyl 3-(4-chlorophenyl)pyruvate was obtained from methyl 3-(4-chlorophenyl)glycidate. The results are shown in the following tables. (Example 17) Starting material: 1.96 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 40 mg (0.10 mmol) Solvent: Benzene (10 ml) Reaction temp.: 60 o C Reaction time: 2 hrs. Yield: 95% (Example 18) Starting material: 1.96 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][ClO₄], 36 mg (0.10 mmol) Solvent: Benzene (10 ml) Reaction temp.: 80 o C Reaction time: 2 hrs. Yield: 92% EXAMPLES 19 and 20 In the same manner as in Example 1, ethyl 3-(4-chlorophenyl)pyruvate was obtained from ethyl 3-(4-chlorophenyl)glycidate. The results are shown in the following tables. (Example 19) Starting material: 1.06 g (5.0 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 40 mg (0.10 mmol) Solvent: Benzene (10 ml) Reaction temp.: 60 o C Reaction time: 2 hrs. Yield: 100% (Example 20) Starting material: 1.50 g (7.1 mmol) Catalyst: [Rh(COD)₂][Tf], 10 mg (0.02 mmol) Solvent: Benzene (10 ml) Reaction temp.: 80 o C Reaction time: 2 hrs. Yield: 90% EXAMPLES 21 to 23 In the same manner as in Example 1, methyl 3-(4-methoxyphenyl)pyruvate was obtained from methyl 3-(4-methoxyphenyl)glycidate. The results are shown in the following tables. (Example 21) Starting material: 2.08 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 40 mg (0.10 mmol) Solvent: Benzene (5 ml) Reaction temp.: 70 o C Reaction time: 2 hrs. Yield: 94% (Example 22) Starting material: 2.08 g (10 mmol) Catalyst: [(MeO-C₈H₁₂)Pd(COD)][Tf], 5.0 mg (0.01 mmol) Solvent: Methylene chloride (10 ml) Reaction temp.: 50 o C Reaction time: 2 hrs. Yield: 100% (Example 23) Starting material: 2.08 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][ClO₄], 3.6 mg (0.01 mmol) Solvent: Benzene (10 ml) Reaction temp.: 70 o C Reaction time: 2 hrs. Yield: 96% EXAMPLE 24 In the same manner as in Example 1, methyl 3-(3-methoxyphenyl)pyruvate was obtained from methyl 3-(3-methoxyphenyl)glycidate. The results are shown in the following table. (Example 24) Starting material: 1.30 g (6.3 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 40 mg (0.10 mmol) Solvent: Benzene (5 ml) Reaction temp.: 70 o C Reaction time: 2 hrs. Yield: 100% EXAMPLE 25 In the same manner as in Example 1, ethyl 3-(3,4-dimethoxyphenyl)pyruvate was obtained from ethyl 3-(3,4-dimethoxyphenyl)glycidate. The results are shown in the following table. (Example 25) Starting material: 2.52 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 40 mg (0.10 mmol) Solvent: Benzene (10 ml) Reaction temp.: 70 o C Reaction time: 2 hrs. Yield: 95% EXAMPLE 26 In the same manner as in Example 1, methyl 3-(2-naphthyl)pyruvate was obtained from methyl 3-(2-naphthyl)glycidate. The results are shown in the following table. (Example 26) Starting material: 2.28 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 40 mg (0.10 mmol) Solvent: Benzene (15 ml) Reaction temp.: 80 o C Reaction time: 2 hrs. Yield: 93% EXAMPLE 27 Methyl 3-methyl-3-(4-isobutylphenyl)glycidate (2.48 g, 10 mmol), allyl(1,5-cyclooctadiene) palladium trifluoromethanesulfonate (40 mg, 0.1 mmol) as a catalyst and toluene (15 ml) as a solvent, were introduced into a 50 ml egg plant type flask, and stirred for 3 hours under reflux. After cooling the reaction mixture, the solvent was distilled off under reduced pressure. Hexane and ether were added to the residue, and the precipitates were filtered off. The solvent was completely removed from the filtrate, whereby 2.36 g of oily substance was obtained. From the nuclear magnetic resonance spectrum and the infrared absorption spectrum, this substance was found to be substantially pure methyl 3-methyl-3-(4-isobutylphenyl)pyruvate. The results are shown in the following table. (Example 27) Starting material: 2.48 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 40 mg (0.10 mmol) Solvent: Benzene (15 ml) Reaction temp.: 110 o C Reaction time: 3 hrs. Yield: 95% EXAMPLE 28 By using zinc perchlorate as a catalyst, in the same manner as in Example 27, methyl 3-methyl-3-(4-isobutylphenyl)pyruvate was obtained from methyl 3-methyl-3-(4-isobutylphenyl)glycidate. The results are shown in the following table. (Example 28) Starting material: 2.48 g (10 mmol) Catalyst: [Zn][ClO₄]₂, 26 mg (0.10 mmol) Solvent: Toluene (15 ml) Reaction temp.: 110 o C Reaction time: 3 hrs. Yield: 80% EXAMPLE 29 Methyl 3-methyl-3-(4-methylphenyl)glycidate was isomerized in the same manner as in Example 27, whereby methyl 3-methyl-3-(4-methylphenyl)pyruvate was obtained. The results are shown in the following table. (Example 29) Starting material: 2.06 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 40 mg (0.10 mmol) Solvent: Toluene (10 ml) Reaction temp.: 110 o C Reaction time: 3 hrs. Yield: 100% EXAMPLES 30 and 31 Methyl 3-methyl-3-phenylglycidate was isomerized in the same manner as in Example 27, whereby methyl 3-methyl-3-phenylpyruvate was obtained. The results are shown in the following tables. (Example 30) Starting material: 1.92 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 40 mg (0.10 mmol) Solvent: Toluene (15 ml) Reaction temp.: 110 o C Reaction time: 2 hrs. Yield: 95% (Example 31) Starting material: 1.92 g (10 mmol) Catalyst: [Zn][ClO₄]₂, 26 mg (0.10 mmol) Solvent: Toluene (15 ml) Reaction temp.: 120 o C Reaction time: 5 hrs. Yield: 90% EXAMPLES 32 to 34 Methyl 3-methyl-3-(4-methoxyphenyl)glycidate was isomerized in the same manner as in Example 27, whereby methyl 3-methyl-3-(4-methoxyphenyl)pyruvate was obtained. The results are shown in the following tables. (Example 32) Starting material: 2.22 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 40 mg (0.10 mmol) Solvent: Toluene (10 ml) Reaction temp.: 110 o C Reaction time: 2 hrs. Yield: 100% (Example 33) Starting material: 2.22 g (10 mmol) Catalyst: [Mg][ClO₄]₂, 140 mg (0.63 mmol) Solvent: Xylene (10 ml) Reaction temp.: 140 o C Reaction time: 2 hrs. Yield: 100% (Example 34) Starting material: 2.22 g (10 mmol) Catalyst: [Rh(COD)₂][Tf], 50 mg (0.10 mmol) Solvent: Toluene (10 ml) Reaction temp.: 110 o C Reaction time: 2 hrs. Yield: 100% EXAMPLE 35 Methyl 3-methyl-3-(4-chlorophenyl)glycidate was isomerized in the same manner as in Example 27, whereby methyl 3-methyl-3-(4-chlorophenyl)pyruvate was obtained. The results are shown in the following table. (Example 35) Starting material: 2.27 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 40 mg (0.10 mmol) Solvent: Toluene (10 ml) Reaction temp.: 110 o C Reaction time: 5 hrs. Yield: 100% EXAMPLE 36 Ethyl 3,3-dimethylglycidate (1.44 g, 10 mmol), allyl(1,5-cyclooctadiene) palladium trifluoromethanesulfonate (40 mg, 0.1 mmol) as a catalyst and benzene (10 ml) as a solvent, were introduced into a 25 ml egg plant type flask, and stirred for 2 hours under reflux. The solvent was removed under reduced pressure, and hexane (about 15 ml) and ether (about 5 ml) were added to the residue. The precipitates were filtered. The solvent was completely distilled off from the filtrate, whereby 1.40 g of oily substance was obtained. From the nuclear magnetic resonance spectrum and the infrared absorption spectrum, this substance was found to be substantially pure ethyl 2-hydroxy-3-methyl-3-butenoate. The yield was 98%. The results are shown in the following table. (Example 36) Starting material: 1.44 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 40 mg (0.10 mmol) Solvent: Benzene (10 ml) Reaction temp.: 60 o C Reaction time: 1 hr. Yield: 98% EXAMPLES 37 and 38 By using ethyl 3,3-dimethylglycidate as a starting material, ethyl 2-hydroxy-3-methyl-3-butenoate was obtained in the same manner as in Example 36. The results are shown in the following tables. (Example 37) Starting material: 1.44 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(NBD)][Tf], 3.9 mg (0.01 mmol) Solvent: Benzene (10 ml) Reaction temp.: 80 o C Reaction time: 2 hrs. Yield: 100% (Example 38) Starting material: 2.00 g (14 mmol) Catalyst: [(MeO-C₈H₁₂)Pd(COD)][Tf], 5.0 mg (0.01 mmol) Solvent: Methylene chloride (10 ml) Reaction temp.: 50 o C Reaction time: 1 hr. Yield: 72% EXAMPLE 39 By using methyl 3,3-diethylglycidate as a starting material, methyl 2-hydroxy-3-ethyl-3-pentenoate was obtained by conducting the reaction in the same manner as in Example 36. The results are shown in the following table. (Example 39) Starting material: 1.58 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 40 mg (0.10 mmol) Solvent: Benzene (10 ml) Reaction temp.: 80 o C Reaction time: 2 hrs. Yield: 100% EXAMPLES 48 to 50 By using ethyl 3-butyl-3-methyl-glycidate as a starting material, the reaction was conducted in the same manner as in Example 36, whereby a mixture comprising ethyl 2-hydroxy-3-methyl-3-heptenoate and ethyl 2-hydroxy-3-butyl-3-butenoate, was obtained. Their production ratios were determined by the nuclear magnetic resonance spectrum. The results are shown in the following tables. (Example 48) Starting material: 1.86 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 40 mg (0.10 mmol) Solvent: Benzene (10 ml) Reaction temp.: 80 o C Reaction time: 2 hrs. Yield: 100% (Example 49) Starting material: 1.00 g (5.4 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][ClO₄], 50 mg (0.14 mmol) Solvent: Benzene (10 ml) Reaction temp.: 60 o C Reaction time: 1 hr. Yield: 100% (Example 50) Starting material: 2.20 g (11.8 mmol) Catalyst: [Rh(COD)₂][ClO₄], 100 mg (0.25 mmol) Solvent: Benzene (10 ml) Reaction temp.: 80 o C Reaction time: 2 hrs. Yield: 95% Ethyl 2-hydroxy-3-methyl-3-heptenoate Ethyl 2-hydroxy-3-butyl-3-butenoate Example 48 70% 30% Example 49 61% 39% Example 50 76% 24% (The production ratios were determined by the integral ratios of the nuclear magnetic resonance spectra.) EXAMPLES 51 to 57 By using methyl 3-methyl-3-phenylglycidate as a starting material, the reaction was conducted in the same manner as in Example 36, whereby methyl 2-hydroxy-3-phenyl-3-butenoate was obtained. The results are shown in the following tables. (Example 51) Starting material: 19.2 g (100 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 403 mg (1 mmol) Solvent: Benzene (100 ml) Reaction temp.: 80 o C Reaction time: 2 hrs. Yield: 100% (Example 52) Starting material: 1.92 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 40 mg (0.10 mmol) Solvent: Benzene (10 ml) Reaction temp.: 60 o C Reaction time: 2 hrs. Yield: 100% (Example 53) Starting material: 1.92 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)[ClO₄], 36 mg (0.10 mmol) Solvent: Benzene (10 ml) Reaction temp.: 80 o C Reaction time: 2 hrs. Yield: 100% (Example 54) Starting material: 1.92 g (10 mmol) Catalyst: [(MeO-C₈H₁₂)Pd(COD)][Tf], 50 mg (0.10 mmol) Solvent: Benzene (10 ml) Reaction temp.: 80 o C Reaction time: 2 hrs. Yield: 95% (Example 55) Starting material: 1.92 g (10 mmol) Catalyst: [Rh(COD)₂][ClO₄], 40 mg (0.10 mmol) Solvent: Benzene (10 ml) Reaction temp.: 80 o C Reaction time: 2 hrs. Yield: 90% (Example 56) Starting material: 1.92 g (10 mmol) Catalyst: [Zn][ClO₄]₂, 26 mg (0.10 mmol) Solvent: Toluene (15 ml) Reaction temp.: 90 o C Reaction time: 2 hrs. Yield: 100% (Example 57) Starting material: 1.92 g (10 mmol) Catalyst: [Mg][ClO₄]₂, 47 mg (0.20 mmol) Solvent: Toluene (15 ml) Reaction temp.: 110 o C Reaction time: 4 hrs. Yield: 100% EXAMPLES 58 and 59 By using methyl 3-methyl-3-(4-methylphenyl)glycidate as a starting material, methyl 2-hydroxy-3-(4-methylphenyl)-3-butenoate was obtained in the same manner as in Example 36. The results are shown in the following tables. (Example 58) Starting material: 2.06 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 4.0 mg (0.01 mmol) Solvent: Benzene (5 ml) Reaction temp.: 80 o C Reaction time: 3 hrs. Yield: 100% (Example 59) Starting material: 10.3 g (50 mmol) Catalyst: [Zn][ClO₄]₂, 132 mg (0.50 mmol) Solvent: Toluene (100 ml) Reaction temp.: 80 o C Reaction time: 2.5 hrs. Yield: 100% EXAMPLES 60 to 64 By using methyl 3-methyl-3-(4-isobutylphenyl)glycidate as a starting material, methyl 2-hydroxy-3-(4-isobutylphenyl)-3-butenoate was obtained in the same manner as in Example 36. The results are shown in the following tables. (Example 60) Starting material: 2.48 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 41 mg (0.10 mmol) Solvent: Benzene (5 ml) Reaction temp.: 80 o C Reaction time: 2 hrs. Yield: 100% (Example 61) Starting material: 2.48 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 0.8 mg (0.002 mmol) Solvent: Benzene (5 ml) Reaction temp.: 75 o C Reaction time: 2 hrs. Yield: 100% (Example 62) Starting material: 2.48 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][ClO₄], 35 mg (0.10 mmol) Solvent: Benzene (10 ml) Reaction temp.: 80 o C Reaction time: 2 hrs. Yield: 100% (Example 63) Starting material: 2.48 g (10 mmol) Catalyst: [Rh(COD₂)][ClO₄], 40 mg (0.10 mmol) Solvent: Benzene (10 ml) Reaction temp.: 80 o C Reaction time: 2 hrs. Yield: 100% (Example 64) Starting material: 2.48 g (10 mmol) Catalyst: [Zn][ClO₄]₂, 26 mg (0.10 mmol) Solvent: Toluene (10 ml) Reaction temp.: 80 o C Reaction time: 2 hrs. Yield: 100% EXAMPLES 65 to 68 By using methyl 3-methyl-3-(4-chlorophenyl)glycidate as a starting material, methyl 2-hydroxy-3-(4-chlorophenyl)-3-butenoate was obtained in the same manner as in Example 36. The results are shown in the following tables. (Example 65) Starting material: 22.7 g (100 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 40 mg (0.10 mmol) Solvent: Benzene (100 ml) Reaction temp.: 80 o C Reaction time: 2 hrs. Yield: 95% (Example 66) Starting material: 2.00 g (8.8 mmol) Catalyst: [Ag][Tf], 10 mg (0.04 mmol) Solvent: Benzene (10 ml) Reaction temp.: 80 o C Reaction time: 2 hrs. Yield: 90% (Example 67) Starting material: 1.02 g (4.5 mmol) Catalyst: [Zn][ClO₄]₂, 3.0 mg (0.01 mmol) Solvent: Benzene (10 ml) Reaction temp.: 80 o C Reaction time: 2 hrs. Yield: 97% (Example 68) Starting material: 1.05 g (4.6 mmol) Catalyst: [Mg][ClO₄]₂, 30 mg (0.13 mmol) Solvent: Benzene (10 ml) Reaction temp.: 80 o C Reaction time: 3 hrs. Yield: 100% EXAMPLE 69 By using methyl 3-methyl-3-(4-cyclohexylphenyl)glycidate, the isomerization reaction was conducted in the same manner as in Example 36, whereby methyl 2-hydroxy-3-(4-cyclohexylphenyl)-3-butenoate was obtained. The results are shown in the following table. (Example 69) Starting material: 13.7 g (50 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 40 mg (0.10 mmol) Solvent: Benzene (100 ml) Reaction temp.: 80 o C Reaction time: 2 hrs. Yield: 100% EXAMPLE 70 By using methyl 3-methyl-3-(4-methoxyphenyl)glycidate, the reaction was conducted in the same manner as in Example 36, whereby methyl 2-hydroxy-3-(4-methoxyphenyl)-3-butenoate was obtained. The results are shown in the following table. (Example 70) Starting material: 2.22 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 40 mg (0.01 mmol) Solvent: Benzene (10 ml) Reaction temp.: 80 o C Reaction time: 2 hrs. Yield: 100% EXAMPLES 71 and 72 By using methyl 3-ethyl-3-phenylglycidate as a starting material, the reaction was conducted in the same manner as in Example 36, whereby methyl 2-hydroxy-3-phenyl-3-pentenoate was obtained. The results are shown in the following tables. (Example 71) Starting material: 2.06 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 40 mg (0.10 mmol) Solvent: Benzene (10 ml) Reaction temp.: 80 o C Reaction time: 2 hrs. Yield: 100% (Example 72) Starting material: 2.06 g (10 mmol) Catalyst: [Zn][ClO₄]₂, 26 mg (0.10 mmol) Solvent: Toluene (15 ml) Reaction temp.: 90 o C Reaction time: 3 hrs. Yield: 100% EXAMPLE 73 By using methyl 3-methyl-3-(2-naphthyl)glycidate as a starting material, methyl 2-hydroxy-3-(2-naphthyl)-3-butenoate was obtained in the same manner as in Example 36. The results are shown in the following table. (Example 73) Starting material: 2.42 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 40 mg (0.10 mmol) Solvent: Benzene (10 ml) Reaction temp.: 80 o C Reaction time: 2 hrs. Yield: 95% EXAMPLES 74 and 75 By using methyl 2,3,3-trimethylglycidate as a starting material, methyl 2-hydroxy-2,3-dimethyl-3-butenoate was obtained by the reaction in the same manner as in Example 36. The results are shown in the following tables. (Example 74) Starting material: 1.44 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 40 mg (0.10 mmol) Solvent: Benzene (10 ml) Reaction temp.: 80 o C Reaction time: 2 hrs. Yield: 100% EXAMPLES 79 to 81 By using methyl 2,3-dimethyl-3-phenylglycidate as a starting material, methyl 2-hydroxy-2-methyl-3-phenyl-3-butenoate was obtained by the reaction conducted in the same manner as in Example 36. The results are shown in the following tables. (Example 79) Starting material: 2.06 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 40 mg (0.10 mmol) Solvent: Benzene (10 ml) Reaction temp.: 80 o C Reaction time: 2 hrs. Yield: 100% (Example 80) Starting material: 2.06 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][ClO₄], 36 mg (0.10 mmol) Solvent: Benzene (10 ml) Reaction temp.: 80 o C Reaction time: 2 hrs. Yield: 100% (Example 81) Starting material: 2.06 g (10 mmol) Catalyst: [Rh(COD)₂][Tf], 40 mg (0.10 mmol) Solvent: Benzene (10 ml) Reaction temp.: 80 o C Reaction time: 2 hrs. Yield: 92% EXAMPLES 82 and 83 By using methyl 2-methyl-3-ethyl-3-(4-fluorophenyl)glycidate as a starting material, methyl 2-hydroxy-2-methyl-3-(4-fluorophenyl)-3-pentenoate was obtained in the same manner as in Example 36. The results are shown in the following tables. (Example 82) Starting material: 2.38 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 140 mg (0.45 mmol) Solvent: Toluene (10 ml) Reaction temp.: 100 o C Reaction time: 6 hrs. Yield: 80% (Example 83) Starting material: 2.38 g (10 mmol) Catalyst: [Zn][ClO₄]₂, 60 mg (0.23 mmol) Solvent: Xylene (10 ml) Reaction temp.: 140 o C Reaction time: 2 hrs. Yield: 86% EXAMPLE 84 By using methyl 2-methyl-3-ethyl-3-(4-chlorophenyl)glycidate as a starting material, methyl 2-hydroxy-2-methyl-3-(4-chlorophenyl)-3-butenoate was obtained in the same manner as in Example 36. The results are shown in the following table. (Example 84) Starting material: 4.88 g (20.3 mmol) Catalyst: [Zn][ClO₄]₂, 10 mg (0.027 mmol) Solvent: Benzene (40 ml) Reaction temp.: 80 o C Reaction time: 5 hrs. Yield: 100% EXAMPLE 85 Methyl 2-hydroxy-3-phenyl-3-butenoate (1.92 g, 10 mmol), allyl(1,5-cyclooctadiene) palladium trifluoromethanesulfonate (40 mg, 0.10 mmol) as a catalyst and toluene (10 ml) as a solvent, were introduced into a 25 ml egg plant type flask, and stirred for 3 hours under reflux. After cooling the reaction mixture, the solvent was distilled off under reduced pressure. Hexane and ether were added to the residue, and the precipitates were filtered off. The solvent was completely distilled off from the filtrate, whereby 1.90 g of oily substance was obtained. From the nuclear magnetic resonance spectrum and the infrared absorption spectrum, this substance was found to be pure methyl 3-methyl-3-phenylpyruvate. The results are shown in the following table. (Example 85) Starting material: 1.92 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 40 mg (0.10 mmol) Solvent: Toluene (10 ml) Reaction temp.: 110 o C Reaction time: 3 hrs. Yield: 100% EXAMPLE 86 By using allyl(1,5-cyclooctadiene) palladium trifluoromethanesulfonate as a catalyst, methyl 2-hydroxy-3-(4-methylphenyl)-3-butenoate was isomerized by the reaction in the same manner as in Example 85, whereby methyl 3-methyl-3-(4-methylphenyl)pyruvate was obtained. The results are shown in the following table. (Example 86) Starting material: 2.06 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 40 mg (0.10 mmol) Solvent: Toluene (10 ml) Reaction temp.: 110 o C Reaction time: 3 hrs. Yield: 96% EXAMPLE 87 By using allyl(1,5-cyclooctadiene) palladium trifluoromethanesulfonate as a catalyst, methyl 2-hydroxy-3-(4-isobutylphenyl)-3-butenoate was reacted in the same manner as in Example 85, whereby methyl 3-methyl-3-(4-isobutylphenyl)pyruvate was obtained. The results are shown in the following table. (Example 87) Starting material: 2.48 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 41 mg (0.10 mmol) Solvent: Toluene (15 ml) Reaction temp.: 110 o C Reaction time: 3 hrs. Yield: 100% EXAMPLE 88 By using allyl(1,5-cyclooctadiene) palladium trifluoromethanesulfonate as a catalyst, methyl 2-hydroxy-3-(4-cyclohexylphenyl)-3-butenoate was reacted in the same manner as in Example 85, whereby methyl 3-methyl-3-(4-cyclohexylphenyl)pyruvate was obtained. The results are shown in the following table. (Example 88) Starting material: 2.00 g (7.3 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 40 mg (0.10 mmol) Solvent: Toluene (15 ml) Reaction temp.: 110 o C Reaction time: 3 hrs. Yield: 85% EXAMPLE 89 By using allyl(1,5-cyclooctadiene) palladium trifluoromethanesulfonate as a solvent, methyl 2-hydroxy-3-(4-chlorophenyl)-3-butenoate was reacted in the same manner as in Example 85, whereby methyl 3-methyl-3-(4-chlorophenyl)pyruvate was obtained. The results are shown in the following table. (Example 89) Starting material: 2.27 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 40 mg (0.10 mmol) Solvent: Toluene (10 ml) Reaction temp.: 110 o C Reaction time: 10 hrs. Yield: 90% EXAMPLE 90 By using allyl(1,5-cyclooctadiene) palladium trifluoromethanesulfonate as a catalyst, methyl 2-hydroxy-3-(4-methoxyphenyl)-3-butenoate was reacted in the same manner as in Example 85, whereby methyl 3-methyl-3-(4-methoxyphenyl)pyruvate was obtained. The results are shown in the following table. (Example 90) Starting material: 2.22 g (10 mmol) Catalyst: [(η³-C₃H₅)Pd(COD)][Tf], 40 mg (0.10 mmol) Solvent: Toluene (10 ml) Reaction temp.: 110 o C Reaction time: 5 hrs. Yield: 100% The nuclear magnetic resonance spectrum data and infrared absorption spectrum data of the arylpyruvates and 2-hydroxycarboxylates obtained by the reactions in Examples 1 to 90, are listed in the following table. EXAMPLE 122 In the same manner as in Example 1, methyl 3-(4-fluorophenyl)pyruvate was obtained from methyl 3-(4-fluorophenyl)glycidate. The results are shown in the following table. (Example 122) Starting material: 2.16 g (11 mmol) Catalyst: [Mg][ClO₄]₂, 101 mg (0.46 mmol) Solvent: Benzene (10 ml) Reaction temp.: 80 ° C Reaction time: 2 hrs. Yield: 10C% EXAMPLE 123 In the same manner as in Example 1, methyl 3-(4-chlorophenyl)pyruvate was obtained from methyl 3-(4-chlorophenyl)glycidate. The results are shown in the following table. (Example 123) Starting material: 2.34 g (11 mmol) Catalyst: [Mg][ClO₄]₂, 103 mg (0.46 mmol) Solvent: Benzene (10 ml) Reaction temp.: 80°C Reaction time: 2 hrs. Yield: 100% EXAMPLE 124 In the same manner as in Example 1, methyl 3-(4-bromophenyl)pyruvate was obtained from methyl 3-(4-bromophenyl)glycidate. The results are shown in the following table. (Example 124) Starting material: 5.14 g (20 mmol) Catalyst: [Mg][ClO₄]₂, 121 mg (0.54 mmol) Solvent: Benzene (20 ml) Reaction temp.: 80°C Reaction time: 2 hrs. Yield: 100% EXAMPLE 125 to 127 The isomerization reaction of methyl 3-methyl-(4-isobutylphenyl)glycidate was conducted in the same manner as in Example 27 except that the reaction was carried out in a sealed tube. The catalyst, the solvent and the reaction conditions are shown in the following table together with the results. (Example 125) Starting material: 1.24 g (5.0 mmol) Catalyst: [Zn][ClO₄]₂·6H₂O, 92 mg (0.25 mmol) Solvent: Toluene (10 ml) Reaction temp.: 140°C (Bath temp.) Reaction time: 2 hrs. Yield: 100% (Example 126) Starting material: 1.24 g (5.0 mmol) Catalyst: [Ag][Tf], 13 mg (0.05 mmol) Solvent: Toluene (5 ml) Reaction temp.: 140°C (Bath temp.) Reaction time: 2 hrs. Yield: 100% (Example 127) Starting material: 1.24 g (5.0 mmol) Catalyst: [Ag][ClO₄], 21 mg (0.1 mmol) Solvent: Benzene (5 ml) Reaction temp.: 120°C (Bath temp) Reaction time: 2 hrs. Yield: 100% REFERENCE EXAMPLE Methyl 3-methyl-3-(4-isobutylphenyl)pyruvate (1.19 g, 4.8 mmol) was dissolved in a 1N sodium hydroxide aqueous solution (15 ml), and a 35% hydrogen peroxide aqueous solution (5.0 ml) was dropwise added under cooling (0 o C) and stirring. The temperature of the mixture was returned to room temperature, and the mixture was stirred overnight. Then, mixture was acidified with hydrochloric acid and extracted with ether, whereby 2-(4-isobutylphenyl)propionic acid (0.78 g, yield: 79%) was obtained. Nuclear magnetic resonance spectrum (CDCl₃, TMS) δ0.88 (d, 6H), 1.46 (d, 3H), 1.83 (d of sep, 1H), 2.42 (d, 2H), 3.65 (q, 1H), 7.08 (m, 4H) Infrared absorption spectrum (neat) νCOOH: 1715 cm⁻¹

Claims: A method for isomerizing a glycidate derivative, characterized in that the isomerization is conducted in the presence of a salt or complex salt represented by the formula: where M is a metal selected from the group consisting of copper, silver, magnesium, barium, calcium, zinc, cadmium, mercury, iron, cobalt, nickel, rhodium, palladium, iridium and platinum, L is a ligand or a mixture of ligands, Y is a perhalogenoate or a sulfonate, m is 0, 1, 2, 3 or 4, and n is 1, 2 or 3 at temperatures in the range of from 40 to 160°C. The method according to claim 1, wherein an arylglycidate represented by the formula: where Ar is an aryl group, R¹ is a hydrogen atom and R² is a methyl, ethyl, isopropyl or t-butyl group, is isomerized in the presence of the salt or complex salt of the formula I to form an arylpyruvate represented by the formula: where Ar, R¹ and R² are as defined above. The method according to claim 1, wherein a glycidate represented by the formula: where each of R³, R⁴, R⁵ and R⁶ is a hydrogen atom, an alkyl group, an aralkyl group or an aryl group, or R³ and R⁴, R³ and R⁶, R⁴ and R⁵ or R⁴ and R⁶ may together form a polymethylene group, and R² is a methyl, ethyl, isopropyl or t-butyl group, is isomerized in the presence of the salt or complex salt of the formula I to form a 2-hydroxy-3-alkenoate represented by the formula: where R², R³, R⁴, R⁵ and R⁶ are as defined above. The method according to Claim 1, wherein the isomerization is conducted in the presence of a salt or complex salt represented by the formula (I) where L is a ligand selected from the group consisting of a π-allyl group, a π-crotyl group, a π-methallyl group, a cyclopentadienyl group, an acetylacetonate group, an 8-methoxy-4-cycloocten-1-yl group, 1,5-cyclooctadiene, cyclooctatetraene, norbornadiene, dicyclopentadiene, benzene, pyridine, bipyridine, triphenylphosphine, triethylphosphine, tri-n-butylphosphine, tricyclohexylphosphine, triphenylphosphite, trimethylphosphite, triethylphosphite and tri-n-butylphosphite. The method according to Claim 1, wherein the isomerization is conducted in the presence of a salt or complex salt represented by the formula (I) where Y is a perchlorate, a periodate, a trifluoromethanesulfonate, a fluorosulfonate, a trifluoromethylbenzenesulfonate or a methanesulfonate.

Inventors: FUCHIKAMI, TAKAMASA, HIRAI, KENJI, HIROSE, HIROAKI, OJIMA, IWAO
Applicants: SAGAMI CHEMICAL RESEARCH CENTER
Application year: 1985
Main classification: B01J31
IPC codes: B01J31, C07C67, C07C69