JPH1171329A - Production of alpha, beta-unsaturated aldehyde and intermediate useful for the production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject compound useful as an intermediate for synthesizing zeatin of plant hormone or the like by reacting a specific compound as a starting raw material with hydrogen and carbon monoxide in the presence of a rhodium compound and a unidentate coordinating tertiary organic phosphorous compound and subsequently subjecting the reaction product to a decarboxylation reaction. SOLUTION: This method for producing the compound of formula III comprises subjecting a compound of formula I (R is a >=2C acyl; X is cyano, an alkoxycarbonyl) (preferably 1-cyano-propenyl acetate or the like) to a hydroformylation reaction in the presence of a rhodium compound [e.g. Rh4 (CO)12 ] and a unidentate coordinating tertiary organic phosphorous compound [preferably tris(2-methylphenyl)phosphite or the like] preferably at 50-100 deg.C under 50-120 atm, and subsequently subjecting the obtained compound of formula II (e.g. 1-cyano-2-formylpropyl acetate) to a decarboxylation reaction in the presence of a catalyst (e.g. sulfuric acid) preferably at 60-120 deg.C under 0.001-10 atm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to the following general formula (1):

[0002]

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The present invention relates to a method for producing an α, β-unsaturated aldehyde represented by the formula (wherein X represents a cyano group or an alkoxycarbonyl group) and an intermediate useful in the method. The α, β-unsaturated aldehyde obtained by the production method of the present invention is, for example, zeatin (Zea) which is a plant hormone.
tin) (see U.S. Pat. No. 4,361,702) and vitamin A acid derivatives (see Japanese Patent Publication No. 3616023 and Japanese Patent Publication No. 60-9493). .

[0004]

2. Description of the Related Art As a method for producing an α, β-unsaturated aldehyde represented by the general formula (1), for example, the following methods are known. A method of condensing pyruvaldehyde diacetal such as pyruvaldehyde dimethyl acetal and acetonitrile, and then hydrolyzing the obtained compound (see U.S. Pat. No. 4,361,702). A method of condensing pyruvaldehyde diacetal with α-trimethylsilyl or phosphonoethyl acetate and then hydrolyzing the obtained compound [Tetrahedron Le
tt., 22 , 1595 (1981)]. Aldol condensation between propionaldehyde and glyoxylate [Helv. Chim. Acta., 45 , 541]
(1962)].

[0005]

However, in the above-mentioned method, a large excess of acetonitrile is used in the condensation of pyruvaldehyde diacetal and acetonitrile, so that the volume efficiency is low and the yield of the condensation product is about 70%. Stays on. In addition, the above-mentioned method requires condensation of pyruvaldehyde diacetal and α-trimethylsilyl or phosphonoethyl acetate at a low temperature such as −78 ° C., so that operability cannot be said to be good, and the yield of the condensation product is also low. About 55% is not enough. Furthermore, in the above method, the yield of aldol condensation is 47%.
And low. As described above, none of the above methods is industrially advantageous as a method for producing an α, β-unsaturated aldehyde represented by the general formula (1). Thus, an object of the present invention is to provide an industrially advantageous method capable of efficiently producing an α, β-unsaturated aldehyde represented by the general formula (1).

[0006]

According to the present invention, the above object is achieved by the following general formula (2)

[0007]

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(Wherein, R represents an acyl group having 2 or more carbon atoms and X represents a cyano group or an alkoxycarbonyl group) of a rhodium compound and a monodentate tertiary organic phosphorus compound. By reacting with hydrogen and carbon monoxide in the presence, the following general formula (3)

[0009]

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Wherein R and X are as defined above, and the resulting compound is subjected to a decarboxylation reaction.

[0011]

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The problem is solved by providing a method for producing an α, β-unsaturated aldehyde represented by the formula: wherein X is as defined above.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION A general formula (2) representing a compound used as a starting material in the present invention, a general formula (3) representing an intermediate, and a general formula representing an α, β-unsaturated aldehyde which is a target compound. In (1), examples of the alkoxycarbonyl group represented by X include a methoxycarbonyl group, an ethoxycarbonyl group, a propoxycarbonyl group,
Examples include an isopropoxycarbonyl group, an n-butoxycarbonyl group, a t-butoxycarbonyl group, a pentoxycarbonyl group, a hexyloxycarbonyl group, and a benzyloxycarbonyl group. In general formulas (2) and (3), examples of the acyl group represented by R and having 2 or more carbon atoms include an acetyl group, a propionyl group,
Butyryl group, isobutyryl group, valeryl group, isovaleryl group, pivaloyl group, hexanoyl group, heptanoyl group, benzoyl group and the like.

Here, specific examples of the compound represented by the general formula (2) used as a starting material in the present invention include 1-cyano-2-propenyl acetate and 1-cyano-2-propenyl acetate.
Cyano-2-propenyl propanoate, 1-cyano-2-propenyl benzoate, 1-methoxycarbonyl-2-propenyl acetate, 1-methoxycarbonyl-2-propenyl = propanoate, 1-ethoxycarbonyl-2 -Propenyl benzoate, 1-t
-Butoxycarbonyl-2-propenyl acetate,
1-benzyloxycarbonyl-2-propenyl acetate and the like. Among these, 1-cyano-2-propenyl acetate, 1-methoxycarbonyl-2-propenyl acetate, 1-t-butoxycarbonyl-2-propenyl acetate, 1-benzyloxycarbonyl-2-propenyl acetate, and the like Are particularly useful in industrially practicing the present invention.

The compound represented by the general formula (2) can be prepared by a known method, for example, i) acrolein is converted into cyanohydrin,
Then, acetic anhydride, propionic anhydride, a method of reacting with carboxylic anhydride such as butanoic anhydride, ii) cyanohydrin acrolein, and then alcoholysis using alcohol such as methanol, ethanol, propanol, isopropanol, butanol and the like. Reaction with carboxylic anhydrides such as acetic anhydride, propionic anhydride, butanoic anhydride (for example, German Patent No. 3634).
151, etc.).

In the present invention, first, the compound represented by the general formula (2) is reacted with hydrogen and carbon monoxide in the presence of a rhodium compound and a monodentate tertiary organic phosphorus compound. It is converted to the compound represented by (3).

As the rhodium compound used in the present invention, any rhodium compound which has a catalytic activity for hydroformylation or which changes to have a catalytic activity for hydroformylation under the conditions of the hydroformylation reaction can be used. Include Rh ₄ (CO) ₁₂ and Rh ₆ (CO)
₁₆ , Rh (acac) (CO) ₂ , rhodium oxide, rhodium chloride, rhodium acetylacetonate, rhodium acetate and the like.

The amount of the rhodium compound to be used is usually in a concentration range of 0.001 mg atom or more in terms of rhodium atom per liter of the hydroformylation reaction solution. 0.1 equivalent of rhodium atom per liter of reaction solution.
It is preferred that the amount be in the concentration range of 01 to 0.25 milligram atoms.

The monodentate tertiary organic phosphorus compound used in the present invention includes, for example, triphenyl phosphite, tris (2-methylphenyl) phosphite, tris (2-ethylphenyl) phosphite,
Tris (2-isopropylphenyl) phosphite, tris (2-phenylphenyl) phosphite, tris (2,6-dimethylphenyl) phosphite, tris (2-t-butylphenyl) phosphite, tris (3
Phosphites such as -methyl-6-t-butylphenyl) phosphite and tris (2,4-di-t-butylphenyl) phosphite; triphenylphosphine, tolylphosphine, tri-n-butylphosphine, −
Examples thereof include phosphines such as n-octylphosphine and tricyclohexylphosphine, and among these, tris (2-methylphenyl) phosphite, tris (2-phenylphenyl) phosphite, and tris (2
-T-butylphenyl) phosphite, tris (3-methyl-6-t-butylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite, and tricyclohexylphosphine are preferred. These monodentate tertiary organic phosphorus compounds may be used alone or in combination of two or more.

The amount of the monodentate tertiary organophosphorus compound to be used is usually in an amount within a concentration range of 0.1 mmol or more per liter of the hydroformylation reaction solution. From the viewpoint, the amount is preferably in a range of 1 to 50 mmol per 1 liter of the hydroformylation reaction solution,
More preferably, the amount is in the concentration range of 2 to 10 mmol per liter.

In the hydroformylation reaction of the present invention, 1,2-bis (diphenylphosphino) ethane, 1,3-bis (diphenylphosphino) propane,
1,4-bis (diphenylphosphino) butane, 1,5
Bidentate diphosphinoalkanes such as -bis (diphenylphosphino) pentane may be added at a ratio of 0.1 to 3 mol per gram atom of rhodium.

The hydroformylation reaction in the present invention comprises
Usually, it is carried out at a temperature in the range of 40 to 120C, preferably 50 to 100C.

The molar ratio of hydrogen to carbon monoxide used in the hydroformylation reaction in the present invention is usually selected from the range of 1/5 to 5/1 (molar ratio) as the gas composition.

The hydroformylation reaction in the present invention comprises
Usually carried out under a pressure in the range of 10 atmospheres or more,
It is preferred to carry out under a pressure in the range of up to 120 atm.

The hydroformylation reaction in the present invention comprises
The reaction may be carried out without using a solvent, or may be carried out in the presence of an organic solvent inert to the reaction. Specific examples of usable solvents include, for example, aromatic hydrocarbons such as benzene, toluene, and xylene; aliphatic hydrocarbons such as hexane and heptane; ethers such as diethyl ether, tetraethylene glycol dimethyl ether, tetrahydrofuran, and dioxane. And halogenated hydrocarbons such as dichloromethane. The solvents may be used alone or in combination of two or more. In addition,
The amount of the solvent to be used is not particularly limited, but is preferably in a range that does not impair the volumetric efficiency of the reaction.

The hydroformylation reaction in the present invention comprises
The reaction can be carried out in a known reaction vessel such as a stirring type reaction vessel or a bubble column type reaction vessel. Further, the reaction may be performed in a batch system or a continuous system.

According to the hydroformylation reaction of the present invention, in addition to the compound represented by the formula (3), the following formula (4)

[0028]

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An aldehyde represented by the formula (wherein R and X are as defined above) is produced in a small amount, but both can be separated by means such as distillation if necessary.

The compound represented by the formula (3) thus obtained is a novel compound. Here, specific examples of the compound represented by the formula (3) include 1-cyano-2-formylpropyl acetate, 1-cyano-2-formylpropyl propionate and 1-cyano-2-formylpropyl butyrate. , 1-cyano-2-formylpropyl = isobutyrate, 1-cyano-2-formylpropyl = valerate, 1-cyano-2-formylpropyl = hexanate, 1-cyano-2-formylpropyl = heptanate, 1-methoxycarbonyl- 2-formylpropyl acetate, 1-methoxycarbonyl-2-formylpropyl propionate, 1-methoxycarbonyl-
2-formylpropyl butyrate, 1-methoxycarbonyl-2-formylpropyl isobutyrate, 1-
Methoxycarbonyl-2-formylpropyl = valerate, 1-methoxycarbonyl-2-formylpropyl =
Hexanat, 1-methoxycarbonyl-2-formylpropyl = heptanate, 1-ethoxycarbonyl-2
-Formylpropyl acetate, 1-ethoxycarbonyl-2-formylpropyl propionate, 1-propoxycarbonyl-2-formylpropyl acetate, 1-propoxycarbonyl-2-formylpropyl propionate, 1-butoxycarbonyl-2-formyl Propyl acetate, 1-butoxycarbonyl-
2-formylpropyl propionate, 1-t-butoxycarbonyl-2-formylpropyl acetate,
1-t-butoxycarbonyl-2-formylpropyl =
Propionate, 1-benzyloxycarbonyl-2-
Formyl propyl acetate, 1-benzyloxycarbonyl-2-formylpropyl = propionate and the like can be mentioned.

In the present invention, the thus obtained compound represented by the formula (3) is converted into an α, β-unsaturated aldehyde represented by the formula (1) by subjecting it to a decarboxylation reaction. Here, as a raw material for the decarboxylic acid reaction, a compound represented by the formula (3) separated and obtained from the above hydroformylation reaction solution by a known method such as distillation may be used. The hydroformylation reaction solution containing the compound shown may be used as it is.

The decarboxylic acid reaction in the present invention is usually carried out by heating the compound represented by the formula (3) in the presence or absence of a catalyst. It is preferable to carry out. Examples of usable catalysts include, for example, sulfuric acid, hydrochloric acid, phosphoric acid,
p-toluenesulfonic acid, alumina, silica alumina,
Acid catalysts such as activated clay and cation exchange resin; and basic catalysts such as sodium hydroxide, potassium hydroxide, triethylamine and triethanolamine.

The amount of the catalyst used is usually 0.01% by weight or more based on the reaction solution in the decarboxylation reaction.
0.05 to 5 with respect to the reaction solution in the decarboxylic acid reaction
% By weight.

In the present invention, the decarboxylation reaction is carried out at 30.
C. is preferably carried out at a temperature of at least 60.degree.
More preferably, it is carried out at a temperature in the range of ° C.

The decarboxylic acid reaction in the present invention is usually carried out under a pressure in the range of 0.001 to 10 atm (absolute pressure). If desired, the reaction can be carried out under reduced pressure while removing the generated carboxylic acid from the reaction system.

The decarboxylic acid reaction in the present invention is usually carried out in the absence of a solvent, but may be carried out in the presence of an organic solvent inert to the reaction. Specific examples of such a solvent include, for example, benzene, toluene,
Aromatic hydrocarbons such as xylene; aliphatic hydrocarbons such as hexane and heptane; diethyl ether, tetraethylene glycol dimethyl ether, tetrahydrofuran,
Ethers such as dioxane; halogenated hydrocarbons such as dichloromethane. These solvents may be used alone or in combination of two or more. The amount of the solvent used is not particularly limited, but is preferably in a range that does not impair the volumetric efficiency of the reaction.

The decarboxylic acid reaction in the present invention can be carried out in a stirred state with the catalyst dissolved or suspended in the liquid phase, or can be carried out in a fixed bed reactor filled with the catalyst. Further, the reaction can be carried out in a batch system or a continuous system.

After completion of the reaction, α, β-
The unsaturated aldehyde can be easily separated and obtained according to a conventional method such as, for example, a method of neutralizing a carboxylic acid generated as desired and then distilling a reaction mixture. The purity of the α, β-unsaturated aldehyde represented by the formula (1) thus obtained can be further increased, if desired, by means such as distillation under reduced pressure or column chromatography.

[0039]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

Example 1 (a) Hydroformylation reaction of 1-cyano-2-propenyl acetate: Dicarbonylacetylacetonate was placed in a 300 ml stainless steel electromagnetically stirred autoclave equipped with a gas inlet and a sampling port and having a capacity of 300 ml. Rhodium 3.9 mg (0.015 mmol), Tris (2,2
485 mg of 4-di-t-butylphenyl) phosphite
(0.75 mmol), 1-cyano-2-propenyl =
30 ml of acetate (30.8 g, 0.246 mol) and 120 ml of toluene were charged in a nitrogen atmosphere without touching air, and the atmosphere in the autoclave was mixed with hydrogen / carbon monoxide = 1/1 (molar ratio). , The pressure inside the autoclave was adjusted to 90 atm with a gas of the same composition, and the internal temperature was raised to 80 ° C while stirring. hydrogen/
The reaction was carried out for 2 hours while supplying a mixed gas of carbon monoxide = 1/1 (molar ratio) to the autoclave and maintaining the pressure in the autoclave at 90 atm. The obtained reaction mixture was analyzed under the following gas chromatography conditions. As a result, 31.1 g of 1-cyano-2-formylpropyl acetate and 1-cyano-4-oxobutyl acetate, which is a linear aldehyde, were obtained. Was found to be produced in an amount of 5.9 g. The conversion of 1-cyano-2-propenyl acetate was 99% and the selectivity for hydroformylation was 98%.

Gas Chromatography Analysis Conditions Column: G-300 (column diameter: 1.2 mm, length:
Column temperature: 100 ° C → 200 ° C (heating rate: 10 ° C)
/ Min)

The resulting reaction mixture was distilled under reduced pressure to obtain 30.7 g (purity: 91%) of 1-cyano-2-formylpropyl acetate as a fraction having a boiling point of 75 ° C. to 81 ° C./1 mmHg. Was. This compound has 2
It was a mixture of different diastereomers (threo and erythro forms). The physical properties are shown below.

Diastereomer (1) ¹ H-NMR (270 MHz, CDCl ₃ , TMS) δ (ppm): 1.39 (d, 3H, J = 6.8H)
z), 2.14 (s, 3H), 3.03 (dq, 1H,
J = 6.0 Hz, 6.8 Hz), 5.66 (d, 1H,
J = 6.0 Hz), 9.67 (s, 1H)

Diastereomer (2) ¹ H-NMR (270 MHz, CDCl ₃ , TMS) δ (ppm): 1.43 (d, 3H, J = 6.7H)
z), 2.14 (s, 3H), 2.95 (dq, 1H,
J = 3.8 Hz, 6.7 Hz), 5.70 (d, 1H,
J = 3.8 Hz), 9.67 (s, 1H)

The ratio of diastereomers calculated from the ¹ H-NMR spectrum was as follows: diastereomer (1)
/ Diastereomer (2) = about 50/50 (molar ratio). In the above-mentioned vacuum distillation, 98 ° C. to 10 ° C.
As a fraction having a boiling point of 2 ° C./1 mmHg, 6.4 g of 1-cyano-4-oxobutyl acetate (purity: 8)
1%). The physical properties of this compound are shown below. ¹ H-NMR (270 MHz, CDCl ₃ , TMS) δ (ppm): 2.15 (s, 3H), 2.22-
2.30 (m, 2H), 2.73 to 2.78 (m, 2
H), 5.41 (t, 1H, J = 5.8 Hz), 9.8
1 (s, 1H)

(B) Decarboxylation reaction: A three-necked flask having an internal volume of 50 ml contains 15 g of the reaction solution obtained according to the method (a) (13.6 g of 1-cyano-2-formylpropyl acetate). ) And 0.15 g of p-toluenesulfonic acid monohydrate were added, the internal temperature was raised to 100 ° C, and the mixture was stirred at normal pressure for 3 hours. After neutralization by adding 0.2 g of triethanolamine to the obtained reaction solution, the above (a)
As a result of analysis under the same gas chromatography conditions as
3-methyl-4-oxo-2-butenenitrile is 7.7
g was formed. The conversion of 1-cyano-2-formylpropyl acetate is 100% and 3
The selectivity to -methyl-4-oxo-2-butenenitrile was 92%. The resulting reaction mixture was distilled under reduced pressure to give 3-methyl-4-oxo-2-butenenitrile (boiling point: 75 ° C to 81 ° C / 1 mmHg, purity: 95
%) Was obtained.

Example 2 (a) Hydroformylation reaction of 1-methoxycarbonyl-2-propenyl acetate: A 300 ml stainless steel electromagnetically stirred autoclave equipped with a gas inlet and a sampling port was charged with dicarbonylacetylacetate. 3.9 mg of natrodium, tris (2,4-di-t
-Butylphenyl) phosphite 485 mg, 1-methoxycarbonyl-2-propenyl acetate 30 ml
(31.8 g, 0.201 mol) and toluene 120
of the autoclave in a nitrogen atmosphere without contacting the air, and the atmosphere in the autoclave was hydrogen / carbon monoxide = 1.
After replacing with a mixed gas of / 1 (molar ratio), the pressure inside the autoclave was adjusted to 90 atm with a gas of the same composition, and the internal temperature was raised to 80 ° C while stirring. Hydrogen / carbon monoxide = 1 /
A 1 (molar ratio) mixed gas was supplied to the autoclave and reacted for 2 hours while maintaining the pressure in the autoclave at 90 atm. The obtained reaction mixture was subjected to (a) of Example 1.
Analysis under the same gas chromatography conditions as in 1-methoxycarbonyl-2-formylpropyl =
It was found that 28.2 g of acetate and 8.4 g of 1-methoxycarbonyl-4-oxobutyl acetate, which is a linear aldehyde, were produced. The conversion of 1-methoxycarbonyl-2-propenyl acetate was 99% and the selectivity for hydroformylation was 98%.

The resulting reaction mixture was distilled under reduced pressure to obtain 28.5 g of 1-methoxycarbonyl-2-formylpropyl acetate as a fraction having a boiling point of 87 ° C. to 89 ° C./1 mmHg (purity 89%). )Obtained. This compound was a mixture of two diastereomers (threo form and erythro form). The physical properties are shown below.

Diastereomer (1) ¹ H-NMR (270 MHz, CDCl ₃ , TMS) δ (ppm): 1.21 (d, 3H, J = 6.5H)
z), 2.16 (s, 3H), 2.96-2.99
(M, 1H), 3.78 (s, 3H), 5.38 (d,
1H, J = 4.2 Hz), 9.69 (s, 1H)

Diastereomer (2) ¹ H-NMR (270 MHz, CDCl ₃ , TMS) δ (ppm): 1.22 (d, 3H, J = 6.5H)
z), 2.13 (s, 3H), 2.96-2.99
(M, 1H), 3.79 (s, 3H), 5.59 (d,
1H, J = 3.0 Hz), 9.67 (s, 1H)

The ratio of diastereomers calculated from the ¹ H-NMR spectrum was as follows: diastereomer (1)
/ Diastereomer (2) = about 59/41 (molar ratio). Further, in the above-mentioned vacuum distillation, 107 ° C. to 1
8.4 g (purity 90%) of 1-methoxycarbonyl-4-oxobutyl acetate was obtained as a fraction having a boiling point of 08 ° C./1 mmHg. The physical properties of this compound are shown below. ¹ H-NMR (270 MHz, CDCl ₃ , TMS) δ (ppm): 2.13 (s, 3H), 2.16 to
2.27 (m, 2H), 2.58 to 2.65 (m, 2
H), 3.75 (s, 3H), 5.04 (dd, 1H,
J = 4.5 Hz, 6.7 Hz), 9.78 (s, 1H)

(B) Decarboxylation reaction: 20 g of the reaction solution obtained according to the above method (a) (containing 18.0 g of 1-methoxycarbonyl-2-formylpropyl acetate) was placed in a 50 ml three-necked flask. ) And 0.5 g of triethanolamine, the internal temperature was raised to 100 ° C, and the mixture was stirred at normal pressure for 3 hours. The obtained reaction mixture was analyzed under the same gas chromatography conditions as in Example 1 (a). As a result, it was found that 10.9 g of methyl 3-methyl-4-oxo-2-butenoate was produced. Was. The conversion of 1-methoxycarbonyl-2-formylpropyl acetate is 100% and 3-methyl-4-oxo-2
-Selectivity to methyl butenoate was 90%. By distilling the obtained reaction mixture under reduced pressure, 3-methyl-
Methyl 4-oxo-2-butenoate (boiling point: 45 ° C.-46
C./3 mmHg, purity: 99%).

Example 3 (a) Hydroformylation of 1-methoxycarbonyl-2-propenyl acetate: In (a) of Example 2, the amount of dicarbonylacetylacetonatotrodium used was changed to 7.8 mg, and The same operation as in (a) of Example 2 was carried out except that the reaction temperature was changed to 60 ° C.,
Hydroformylation of -methoxycarbonyl-2-propenyl acetate was carried out. The obtained reaction mixture was analyzed under the same gas chromatography conditions as in Example 1 (a). As a result, 11.1-methoxycarbonyl-2-formylpropyl acetate was 31.1 g, and 1-methoxycarbonyl-4- was obtained. It was found that 5.5 g of oxobutyl acetate was produced. The conversion of 1-methoxycarbonyl-2-propenyl acetate is 99
% And the hydroformylation selectivity was 98%.

(B) Decarboxylation reaction 50 g of the reaction solution obtained in the above (a) (11.1 g of 1-methoxycarbonyl-2-formylpropyl acetate)
Was carried out in the same manner as in Example 2 (b), and the resulting reaction mixture was analyzed under the same gas chromatography conditions as in Example 1 (a). It was found that 7.0 g of methyl 4-oxo-2-butenoate was produced. The conversion of 1-methoxycarbonyl-2-formylpropyl acetate is 100%,
The selectivity to methyl 3-methyl-4-oxo-2-butenoate was 93%.

[0055]

According to the present invention, the α, β-unsaturated aldehyde represented by the above formula (1) can be produced efficiently and industrially advantageously.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C07C 67/313 C07C 67/313 69/716 69/716 Z 253/30 253/30 255/17 255/17 // C07B 61 / 00 300 C07B 61/00 300

Claims (2)

[Claims] 1. The following general formula (2): (Wherein, R represents an acyl group having 2 or more carbon atoms and X represents a cyano group or an alkoxycarbonyl group) in the presence of a rhodium compound and a monodentate tertiary organic phosphorus compound. By reacting with hydrogen and carbon monoxide, the following general formula (3): Wherein R and X are as defined above, and the resulting compound is subjected to a decarboxylation reaction, wherein the compound has the following general formula (1): Wherein X is as defined above, α,
Method for producing β-unsaturated aldehyde. 2. The following general formula (3): (Wherein, R represents an acyl group having 2 or more carbon atoms, and X represents a cyano group or an alkoxycarbonyl group).