JP5144138B2 - Process for producing α-methylene-β-alkyl-γ-butyrolactone - Google Patents

Description

  The present invention relates to α-methylene-β-alkyl-γ-butyrolactone or α-methylene-β-alkyl-γ-alkyl-γ-butyrolactone (hereinafter collectively referred to as α-methylene-β-alkyl-γ-butyrolactone). A manufacturing method). α-methylene-β-alkyl-γ-butyrolactones can be molded with methacrylic acid esters or styrene to produce a molding material having a high glass transition temperature.

  Numerous reports have been made so far regarding methods for producing α-methylene-γ-butyrolactones such as α-methylene-β-alkyl-γ-butyrolactone and α-methylene-γ-butyrolactone. For example, review articles are described in Non-Patent Document 1, Non-Patent Document 2, and Non-Patent Document 3, but when these production methods are roughly classified, γ-butyrolactones are synthesized by some method, and the α position is determined. The method can be divided into a method of introducing a methylene group by activation and a method of producing α-methylene-γ-butyrolactone using an existing olefin. Hereinafter, these reported manufacturing methods will be described.

There is a method of introducing a carboxyl group to activate the α-position of the lactone ring. Non-Patent Document 4 describes a method represented by the following scheme in which a carboxyl group is introduced into the α-position of a lactone ring with carbon dioxide gas, and a methylene group is introduced in the presence of a 37% formaldehyde aqueous solution, diethylamine, and acetic acid / sodium acetate. ing. However, since this method uses LDA (lithium diisopropylamide: LiN (iPr) ₂ ), which is an expensive reagent, it is not an industrial production method.

  Non-Patent Document 5 describes a method for introducing an alkyloxalyl group for activating the α-position of a lactone ring. Here, ethyl oxalylation is carried out at the α-position of the lactone ring with metallic sodium, absolute ethanol and diethyl oxalate. A method for producing α-methylene-γ-butyrolactone by neutralizing a sodium salt of an oxalyl derivative in a reaction solution, extracting the oxalyl derivative, and reacting the concentrated residue with lithium hydride and gaseous formaldehyde is described. Has been.

  Similarly, in Non-Patent Document 6, spiro derivatives are produced by treating with ethyl oxalyl at the α-position of the lactone ring by a one-pot reaction and then treating with formaldehyde gas. The spiro derivative is extracted by repeatedly washing the concentrated residue of this reaction solution with ether, and then induced to α-methylene-γ-butyrolactone by reacting this extract with an aqueous sodium hydrogen carbonate solution, followed by re-distillation. Describes a process for producing α-methylene-γ-butyrolactone with high purity.

  However, since these methods use gaseous formaldehyde, it is necessary to install a formaldehyde gas generator in the manufacturing process, or to perform manufacturing at a location adjacent to the factory where formaldehyde gas is generated. It's hard to say how. In addition, since oxalyl derivatives and intermediate spiro derivatives are neutral compounds that are easily soluble in water, they must be extracted and isolated with a large amount of solvent and then subjected to a reaction under basic conditions. It is hard to say that it is a simple manufacturing method. Furthermore, only α-methylene-γ-butyrolactone having no substituent is described, and the yield is not satisfactory.

On the other hand, Non-Patent Document 7 describes a method shown in the following scheme in which the α-position of the lactone ring is activated by a one-pot reaction and then methyleneated with a 37% formaldehyde aqueous solution. Since sodium hydride is used, it is difficult to say that it is a practical production method. In addition, the yield is relatively good when R ₁ and R ₂ are aromatic groups, but there is a problem that the yield is low in a compound that is not an aromatic group but an alkyl group or a hydrogen atom.

  In Non-Patent Documents 5 to 7, the raw material γ-butyrolactone is reacted with 1 to 1.1 equivalents of an oxalate ester and a base. However, γ-butyrolactones having a β substituent are alkylated. It is difficult to completely consume the raw material because the salt formed by the oxalation precipitates with the progress of the reaction, and it is difficult to produce high-purity α-methylene-γ-butyrolactone when the raw material remains. It was difficult.

  In Patent Document 1, 2-methylene-3-methyl-4-hydroxybutyraldehyde and / or the tautomer 2-hydroxy-3-methylene-4-methyltetrahydrofuran or 2-methylene-3-methyl-4 -Α-methylene-β-methylbutyrolactone is produced by oxidizing acetoxybutyraldehyde in the presence of an oxidizing agent followed by cyclization.

  However, the described method mainly uses homogeneous oxidizing agents such as peracetic acid and sulfuric acid, and the oxidizing method cannot be used repeatedly. It's hard to say. Further, although a method of liquid phase oxidation in a heterogeneous system such as silver oxide or manganese oxide has been shown, it is not a method of oxidizing using molecular oxygen.

As described above, various production methods for α-methylene-γ-butyrolactone such as α-methylene-β-alkyl-γ-butyrolactone have been developed, but the reagents used are expensive and The rate was unsatisfactory, and it was necessary to use raw materials that are highly toxic and difficult to handle, such as formaldehyde gas. Therefore, all of them have serious industrial problems, and are not always satisfactory as practical industrial production methods that can be easily produced at low cost.
JP 10-147581 A Synthesis 1975, 67-82. Synthesis 1986, 157-183 Synth. Commun. 1975, 5, 245-268 Chem. Comm. 1973, 500-501 J. et al. Org. Chem. 1977, 42, 1180-1185 Macromolecules 1979, 12, 546-551. Agric. Biol. Chem. 1978, 42, 1585-1588

  Accordingly, an object of the present invention is to provide a method for producing α-methylene-β-alkyl-γ-butyrolactone inexpensively and easily.

  As a result of intensive studies to solve the above-mentioned problems, the present inventor has found that 2-methylene-3-alkyl-4-hydroxybutyraldehyde and / or its tautomer in the liquid phase, molecular oxygen and catalyst. The present invention has been achieved by finding a method capable of producing α-methylene-β-alkyl-γ-butyrolactones inexpensively and easily in high yield by oxidation in the presence.

  That is, the present invention provides the following general formula (I)

[In Formula (I), R ¹ represents a linear or branched alkyl group having 1 to 10 carbon atoms, and R ² represents a hydrogen atom or a linear or branched alkyl group having 1 to 10 carbon atoms. ]
Which comprises a step of oxidizing a 2-methylene-3-alkyl-4-hydroxybutyraldehyde and / or its tautomer represented by the following formula in the liquid phase in the presence of molecular oxygen and a catalyst: II)

Wherein ^(II), R 1, ^{R 2} have the same meanings as ^R 1, ^{R 2} in formula (I). ]
The manufacturing method of (alpha) -methylene- (beta) -alkyl-gamma-butyrolactone represented by these.

  In the oxidation step of the compound (I) and / or its tautomer, a metal-supported catalyst is used as a catalyst.

As R ¹ in the general formulas (I) and (II), the glass transition temperature (heat resistance) of a polymer obtained from α-methylene-β-alkyl-γ-butyrolactones of the formula (II) is improved. From the viewpoint of the effect, lower alkyl groups such as methyl group, ethyl group, propyl group and isopropyl group are preferred. Thus, by having an alkyl group at the β-position, the glass transition temperature of the polymer is specifically increased. Further, R ² in the formulas (I) and (II) is preferably a hydrogen atom.

  According to the present invention, α-methylene-β-alkyl-γ-butyrolactone can be efficiently produced from an inexpensive raw material. Further, the use of a heterogeneous catalyst (solid catalyst) facilitates catalyst separation after the oxidation step, and the recovered catalyst is industrially advantageous because it can be reused.

  Hereinafter, the compound represented by formula (I) is referred to as compound (I). The same applies to compounds represented by other formulas.

  As described in Patent Document 1, the compound (I) is in equilibrium with 2-hydroxy-3-methylene-4-alkyltetrahydrofurans represented by the following general formula (I ′) as tautomers. Exists.

In [Formula (I ^'), R 1, ^{R 2} is identical to ^R 1, ^{R 2} in formula (I). ]

  The compound (I) and / or its tautomer (I ′) in the present invention comprises, for example, a Group 8-10 metal and a phosphine ligand or phosphite ligand as described in Patent Document 1. From the hydroformylation reaction in the presence of a catalyst system, the following general formula (III)

Wherein ^(III), R 1, ^{R 2} have the same meanings as ^R 1, ^{R 2} in formula (I). ]
Can be produced by a method such as via a Mannich reaction.

  Hereinafter, Production Examples of Compound (I) and / or its tautomer (I ′) will be described using Compound (III) as a raw material.

  As the catalyst, a reaction using a secondary amine and an inorganic or organic acid (European Patent No. 58927 (BASF, 1982) and JP-A-11-322647 (Kuraray, 1999)) is suitable. .

  Said compound (III) can be reacted with formaldehyde, advantageously in the presence of a secondary amine and an acid, to form said compound (I) and / or its tautomer (I ').

  As the formaldehyde source, for example, an aqueous formalin solution or paraformaldehyde can be used.

  From the viewpoint of reaction yield and selectivity, the secondary amine used in the reaction is particularly desirable as follows. Specific examples include diethylamine, dibutylamine, dibenzylamine, piperidine, morpholine, diethanolamine, 2-methylamineethanol, and the like.

  Examples of the acid used in the reaction include mineral acids such as hydrochloric acid, sulfuric acid, phosphoric acid and nitric acid, acetic acid, butyric acid, formic acid, benzoic acid, succinic acid, salicylic acid, terephthalic acid, toluic acid, propionic acid, p-toluenesulfonic acid, etc. Organic acids can be mentioned.

  It should be understood that the secondary amines and acids that can be used are not limited to the examples already given.

  Next, in the presence of a catalyst, the compound (I) and / or its tautomer (I ′) is contacted with molecular oxygen to oxidize, and α-methylene-β-alkyl-γ of the general formula (II) -The process of obtaining butyrolactones (see the following reaction formula) will be described in detail.

  The contacting order of the compound (I) and / or its tautomer (I ′), solvent and catalyst is not limited, and for example, these substances may be charged into the reactor at once.

  Examples of the catalyst to be used include metal-supported catalysts, metal oxides, metal salts, and the like. Among them, the reaction solution and the catalyst can be easily separated by a solid-liquid separation means such as filtration after the reaction. A homogeneous catalyst (solid catalyst) is preferred, and a metal-supported catalyst is more preferred. As the active component of the metal-supported catalyst, for example, palladium, ruthenium, rhodium, iridium, platinum, gold, osmium, silver, lead, mercury, bismuth, thallium and other metal elements, a plurality of these metal elements And alloys containing these metal elements and other metal elements, and compounds containing these metal elements. Of these, metallic palladium is desirable.

  The metal-supported catalyst includes different elements such as tellurium, nickel, chromium, cobalt, indium, tantalum, copper, zinc, zirconium, hafnium, tungsten, manganese, rhenium, antimony, tin, bismuth, titanium, aluminum, boron, Silicon or the like may be included.

  Examples of the support for the metal-supported catalyst include metal oxides (silica, alumina, titania, zirconia, magnesia, etc.), composite metal oxides (silica-alumina, titania-silica, silica-magnesia, etc.), zeolite (ZSM- 5), inorganic oxides such as mesoporous silicate (MCM-41, etc.); natural minerals (clay, diatomaceous earth, pumice, etc.); various carriers of carbon materials (activated carbon, graphite, etc.).

  The composition ratio of the metal-supported catalyst can be arbitrarily changed, and is not particularly limited. In general, the metal as an active component is 0.5 to 30% by mass, preferably 1 to 20% by mass per carrier mass. %, More desirably 1 to 15% by mass. In addition, although there is no limitation in particular in the usage-amount of the catalyst with respect to a raw material, 1 / 1000-5 times are preferable by mass ratio. However, the present invention is not limited to this range.

  The metal-supported catalyst is preferably subjected to a reduction treatment before use. The reducing agent to be used is not particularly limited, and examples thereof include hydrazine, formalin, sodium borohydride, hydrogen, formic acid, formic acid salt, ethylene, propylene, and isobutylene. The temperature and reduction time of the system at the time of reduction vary depending on the reduction method, the metal compound used, the solvent, the reducing agent, and the like. The time is 0.5 to 24 hours.

  The molecular oxygen source is not particularly limited, and for example, a mixed gas of molecular oxygen and other gas, a molecular oxygen-containing gas such as pure oxygen gas, or the like can be used. Examples of the mixed gas include a mixed gas of inert gas and molecular oxygen and air. Examples of the inert gas include nitrogen, helium, argon, carbon dioxide and the like. Molecular oxygen may be introduced from outside the system, or may be generated inside the system. The amount of molecular oxygen used varies depending on the type of substrate, but it is preferably 0.5 mol or more, more preferably 1 mol or more, still more preferably 2 or more, and preferably 100 mol or less with respect to 1 mol of the substrate. 50 mol or less is more preferable. Often an excess of molecular oxygen is used relative to the substrate.

  Further, by bubbling a molecular oxygen-containing gas into the reaction solution, polymerization can be prevented simultaneously with the oxidation reaction. The amount of the molecular oxygen-containing gas such as air to be introduced can be appropriately set so that the desired reaction progress and polymerization preventing effect can be obtained. For example, when air is used as the molecular oxygen-containing gas, it is preferable to react the substrate while bubbling at 0.5 ml / min or more with respect to 1 mol of the raw material used. The reaction is carried out while a polymerization inhibitor is present in the reaction solution containing the compound (I) and / or its tautomer (I ′) and a molecular oxygen-containing gas such as air is introduced into the reaction solution. Is particularly preferable from the viewpoint of amplification of the polymerization preventing effect.

  Although the oxidation reaction of the present invention proceeds even without solvent, it is desirable to use a solvent in view of the reaction yield. Examples of the solvent used at this time include alcohols such as methanol, ethanol, i-propanol, n-butanol and t-butanol, esters such as ethyl acetate and butyl acetate, diethyl ether, diisopropyl ether, t-butyl methyl ether, Ethers such as tetrahydrofuran and dioxane, aromatic compounds such as toluene and xylene, alkanes such as pentane, hexane, heptane, octane and cyclohexane, dimethylsulfoxide, dimethylformamide, polar solvents such as water, acetonitrile and propionitrile, Halides such as chloroform and dichloromethane are exemplified. These solvents may be used alone or in combination.

  The amount of the solvent is preferably 0.01 to 100 times the mass of the compound (I) and / or its tautomer (I ′), and is preferably 1 to 50 times considering the cost. Double is even more desirable.

  The reaction temperature is not particularly limited, but it is preferably 0 ° C. or higher and the boiling point of the solvent or lower, preferably 20 to 200 ° C., more preferably 50 to 110 ° C. in consideration of the reaction rate and reaction yield.

  Although reaction time is not specifically limited, 0.1 to 100 hours are desirable, and considering reaction yield, 0.5 to 70 hours are desirable, and 1 to 40 hours are more desirable.

  The pressure of the reaction system is not particularly limited, but is preferably 1 to 100 atm, more preferably 1 to 70 atm, and further preferably 1 to 50 atm considering the cost required for the reaction apparatus.

  As a method for recovering the α-methylene-β-alkyl-γ-butyrolactone produced after the reaction, a method of filtering the reaction solution and concentrating the obtained filtrate under reduced pressure is desirable.

  Thereafter, purification operations such as vacuum distillation and thin film distillation can be performed to obtain the product. At that time, in order to prevent polymerization of α-methylene-β-alkyl-γ-butyrolactone, it is preferable to have a polymerization inhibitor present in the system. The type of the polymerization inhibitor is not particularly limited, and may be used alone or in combination of two or more.

  The polymerization inhibitor may be added, for example, when the raw materials are charged before the reaction, or may be added to the reaction solution in the oxidation step, may be added to the extract, or may be added before distillation.

  Examples of the polymerization inhibitor include hydroquinone, p-methoxyphenol, 2,4-dimethyl-6-tert-butylphenol, 2,6-di-tert-butyl-4-methylphenol, tert-butyl-catechol, 2,6- Phenols such as di-tert-butyl-4-methylphenol, pentaerythritol, tetrakis (3,5-di-tert-butyl-4-hydroxyhydrocinnamate), 2-sec-butyl-4,6-dinitrophenol Compound, N, N'-diisopropylparaphenylenediamine, N, N'-di-2-naphthylparaphenylenediamine, N-phenylene-N '-(1,3-dimethylbutyl) paraphenylenediamine, N, N'- Bis (1,4-dimethylphenyl) -paraphenylenediamine, N- (1,4 Amine compounds such as (dimethylphenyl) -N′-phenyl-paraphenylenediamine, 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl, 4-benzoyloxy-2,2,6,6 -N-oxyl compounds such as tetramethylpiperidine-N-oxyl and bis (1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) sebacate, copper, copper chloride (II), iron chloride And metal compounds such as (III).

  Although the usage-amount of a polymerization inhibitor should just be determined suitably, 100 ppm or more is preferable with respect to (alpha) -methylene- (beta) -alkyl-gamma-butyrolactone (II), and 500 ppm or more is more preferable in order to fully exhibit an effect. On the other hand, in view of cost, the amount of the polymerization inhibitor used is preferably 10,000 ppm or less, more preferably 5000 ppm or less.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in more detail, this invention is not limited to an Example.

The product was identified with a nuclear magnetic resonance apparatus ( ¹ H-NMR), and the purity analysis was performed with gas chromatography (GC).

<Synthesis example>
2-methylene-3-methyl-4-hydroxybutyraldehyde and its tautomer used in Examples and Comparative Examples were synthesized as follows. That is, 122.6 g of 2-hydroxy-4-methyl-tetrahydrofuran, 25.2 g of diethanolamine, 14.4 g of acetic acid, and 112.0 g of a 37% aqueous formaldehyde solution were added to 600 g of toluene and heated at 60 ° C. for 5 hours. The reaction solution was extracted three times with 600 g of toluene, the solvent was distilled off under reduced pressure, and the residue was distilled under reduced pressure to obtain 105.5 g of 2-methylene-3-methyl-4-hydroxybutyraldehyde containing a tautomer. . (Yield 77%)
<Comparative Example 1>
Synthesis of α-methylene-β-methyl-γ-butyrolactone 11.4 g of 2-methylene-3-methyl-4-hydroxybutyraldehyde and 4-benzoyloxy-2 containing tautomer in 114.14 g of t-butanol , 2,6,6-tetramethylpiperidine-N-oxyl 11.4 mg was added, heated to 70 ° C. under normal pressure, and air was introduced from the bottom of the reactor at a flow rate of 40 ml / min. Even after 5 hours, no α-methylene-β-methyl-γ-butyrolactone was formed.

<Example 1>
Synthesis of α-methylene-β-methyl-γ-butyrolactone 111.4 g of t-butanol was added to 11.4 g of 2-methylene-3-methyl-4-hydroxybutyraldehyde and 4-benzoyloxy-2 containing tautomers. , 2,6,6-tetramethylpiperidine-N-oxyl 5.7 mg was added, followed by 0.57 g of 5% palladium / carrier alumina. Under normal pressure, the reaction temperature was 70 ° C., and air was introduced from the bottom of the reactor at a flow rate of 40 ml / min. After 15 hours, the reaction solution was filtered, and the filtrate was concentrated under reduced pressure and distilled under reduced pressure to obtain 7.3 g of α-methylene-β-methyl-γ-butyrolactone. (Yield 68%)

<Example 2>
Synthesis of α-methylene-β-methyl-γ-butyrolactone In Example 1, the reaction was carried out in the same manner except that the catalyst was replaced with 5% ruthenium / carrier titania. α-methylene-β-methyl-γ- 7.6 g of butyrolactone was obtained. (Yield 65%)

<Example 3>
Synthesis of α-methylene-β-methyl-γ-butyrolactone In Example 1, the reaction was carried out in the same manner except that the catalyst was replaced with 10% platinum / support silica-alumina. α-methylene-β-methyl- 7.1 g of γ-butyrolactone was obtained. (Yield 63%)

<Example 4>
Synthesis of α-methylene-β-methyl-γ-butyrolactone A stainless steel bubble column reactor (internal volume 150 ml) was charged with 34.2 g of t-butanol and 2-methylene-3-methyl-4 containing tautomers. -3.42 g of hydroxybutyraldehyde, 3.4 mg of 4-benzoyloxy-2,2,6,6-tetramethylpiperidine-N-oxyl, 0.17 g of 5% palladium / carrier alumina were added. The reaction was performed at a reaction temperature of 90 ° C. and a reaction pressure of 30 atm while adjusting the amount of oxygen so that the inlet oxygen concentration was 10% by volume. After 2 hours, the pressure was released and the reaction solution was filtered. The filtrate was concentrated under reduced pressure and distilled under reduced pressure to obtain 1.51 g of α-methylene-β-methyl-γ-butyrolactone (yield 45%).

<Example 5>
Synthesis of α-methylene-β-methyl-γ-butyrolactone In Example 4, the reaction was carried out in the same manner except that the catalyst was replaced with 5% ruthenium / carrier titania. α-methylene-β-methyl-γ- 1.74 g of butyrolactone was obtained. (Yield 52%)

<Example 6>
Synthesis of α-methylene-β-methyl-γ-butyrolactone To 57.1 g of tetrahydrofuran, 11.4 g of 2-methylene-3-methyl-4-hydroxybutyraldehyde containing tautomers and 5.7 mg of p-methoxyphenol were added. Then, 0.45 g of 5% palladium-3% bismuth-1% zinc / carrier alumina was added. Under normal pressure, the reaction temperature was 70 ° C., and air was introduced from the lower part of the reactor at a flow rate of 40 ml / min. After 15 hours, the reaction solution was filtered, and the filtrate was concentrated under reduced pressure and distilled under reduced pressure to obtain 8.4 g of α-methylene-β-methyl-γ-butyrolactone. (Yield 75%)

<Example 7>
Synthesis of 2-methylene-3-ethyl-4-methyl-4-hydroxybutyraldehyde and its tautomer To 130 g of toluene, 26.0 g of 2-hydroxy-4-ethyl-5-methyl-tetrahydrofuran and 2-methylamine Ethanol 3.0 g, acetic acid 2.4 g and 37% formaldehyde aqueous solution 18.7 g were added and heated at 60 ° C. for 6 hours. The reaction solution was extracted 3 times with 100 g of toluene, the solvent was distilled off under reduced pressure, and the residue was subjected to distillation under reduced pressure to give 20 methylene 2-methyl-3-ethyl-4-methyl-4-hydroxybutyraldehyde containing tautomers. .5 g was obtained. (Yield 72%)

Synthesis of α-methylene-β-ethyl-γ-methyl-γ-butyrolactone 2-methylene-3-ethyl-4-methyl-4-hydroxybutyraldehyde 14 containing 142.2 g of the obtained tautomer 0.2 g and 7.1 mg of p-methoxyphenol were added, followed by 1.42 g of 10% rhodium / supported activated carbon. Under normal pressure, the reaction temperature was 80 ° C., and air was introduced from the bottom of the reactor at a flow rate of 20 ml / min. After 35 hours, the reaction solution was filtered, and the filtrate was concentrated under reduced pressure and distilled under reduced pressure to obtain 9.9 g of α-methylene-β-ethyl-γ-methyl-γ-butyrolactone. (Yield 71%)

<Example 8>
Synthesis of 2-methylene-3-propyl-4-hydroxybutyraldehyde and its tautomer To 130 g of toluene, 26.0 g of 2-hydroxy-4-propyl-tetrahydrofuran, 4.2 g of diethanolamine, 2.4 g of acetic acid, 37% 18.7 g of an aqueous formaldehyde solution was added and heated at 60 ° C. for 5 hours. The reaction solution was extracted 3 times with 100 g of toluene, the solvent was distilled off under reduced pressure, and the residue was distilled under reduced pressure to obtain 21.0 g of 2-methylene-3-propyl-4-hydroxybutyraldehyde containing a tautomer. . (Yield 74%)

Synthesis of α-methylene-β-propyl-γ-butyrolactone 14.2 g of 2-methylene-3-propyl-4-hydroxybutyraldehyde and p-methoxyphenol 14 containing 142.2 g of the obtained tautomer .2 mg was added followed by 0.71 g of 5% palladium / carrier alumina. Under normal pressure, the reaction temperature was 80 ° C., and air was introduced from the bottom of the reactor at a flow rate of 20 ml / min. After 25 hours, the reaction solution was filtered, and the filtrate was concentrated under reduced pressure and distilled under reduced pressure to obtain 10.1 g of α-methylene-β-propyl-γ-butyrolactone. (Yield 72%)

Claims (2)

(1) The following general formula (I)

[In Formula (I), R ¹ represents a linear or branched alkyl group having 1 to 10 carbon atoms, and R ² represents a hydrogen atom or a linear or branched alkyl group having 1 to 10 carbon atoms. ]
Which comprises a step of oxidizing a 2-methylene-3-alkyl-4-hydroxybutyraldehyde and / or its tautomer represented by the following formula in the liquid phase in the presence of molecular oxygen and a catalyst: II)

Wherein ^(II), R 1, ^{R 2} have the same meanings as ^R 1, ^{R 2} in formula (I). ]
The manufacturing method of (alpha) -methylene- (beta) -alkyl-gamma-butyrolactone represented by these.   The α-methylene-β-alkyl-γ-butyrolactone according to claim 1, wherein a metal-supported catalyst is used as a catalyst in the oxidation step of the formula (I) and / or a tautomer thereof. Production method.