JP5814782B2 - Method for producing cyclopentanone derivative - Google Patents

Description

  The present invention relates to a method for producing a cyclopentanone derivative that can be an intermediate of a methyl (3-oxocyclopentyl) acetate derivative useful as a perfume material.

Methyl (3-oxocyclopentyl) acetate derivatives having a hydrocarbon group at the 2-position include methyl dihydrojasmonate (methyl (3-oxo-2-pentylcyclopentyl) acetate) and methyl jasmonate, particularly jasmine-like fragrances. It is useful as a fragrance material having
As the intermediate, for example, 2- (3-oxocyclopentyl) malonate having a hydrocarbon group at the 2-position is known, and the production method is 2-cyclopenten-1-one having a hydrocarbon group at the 2-position. A Michael addition reaction between benzene and an ester compound is known.
The Michael addition reaction is generally performed in the presence of a homogeneous base catalyst. For example, Patent Document 1 and Non-Patent Document 1 describe unsaturated alicyclic ketones by Michael addition reaction using a base catalyst such as sodium methoxide. A manufacturing method is disclosed.
Patent Document 2 and Non-Patent Documents 2 and 3 disclose a method for producing a Michael addition reaction product using an apatite solid catalyst or the like in which an asymmetric carboxylic acid is immobilized.

Japanese National Patent Publication No. 10-504325 JP 2008-246401 A

G.BUGHI, B.ECCEIZ, J. Org. Chem., 1971, 36, 2021 H. Kabashima, H. Tsuji, T. Shibuya, H. Hattori, J. Mol. Cat. A Chemical, 2000, 155, 23 B. Veldurthy, J.M.Clacens, F.A. Figueras, Adv. Synth. Catal. 2005, 347, 767

When a 2- (3-oxocyclopentyl) malonate, which is an intermediate of the methyl dihydrojasmonate, is used, a homogeneous catalyst such as sodium methoxide is used as a post-treatment step. Through many steps such as solvent removal, not only production efficiency decreased, but also yield and quality decreased.
On the other hand, when a solid catalyst is used, the post-treatment process is expected to be simplified. However, the Michael addition reaction disclosed in Patent Document 2, Non-Patent Documents 2 and 3 uses a carbon-carbon unsaturated bond moiety as a substrate. However, there is no disclosure of the Michael addition reaction for a substrate having a hydrocarbon group.
An object of the present invention is to provide an efficient method for producing a cyclopentanone derivative that can be an intermediate of a methyl (3-oxocyclopentyl) acetate derivative useful as a perfume material.

As a result of studying a catalyst used in a Michael addition reaction between a 2-cyclopenten-1-one derivative having a hydrocarbon group at the 2-position and an ester compound, the present inventors have found a solid base catalyst supporting a specific conjugated base. It was found that a cyclopentanone derivative that can be an intermediate of the methyl (3-oxocyclopentyl) acetate derivative can be obtained efficiently by using.
That is, the present invention provides the following [1] and [2].
[1] In the presence of a solid base catalyst containing a phosphazene base or a guanidine base, a 2-cyclopenten-1-one derivative represented by the general formula (I) and an ester compound represented by the general formula (II) are mixed with Michael. A method for producing a cyclopentanone derivative represented by the general formula (III), which is subjected to addition reaction.

（式中、Ｒ¹は炭素数１〜１０の炭化水素基を示す。）

(In the formula, R ¹ represents a hydrocarbon group having 1 to 10 carbon atoms.)

（式中、Ｒ²は炭素数１〜４のアルキル基を示し、Ｒ³は炭素数１〜４のアルキル基又はアルコキシ基を示す。）

(In the formula, R ² represents an alkyl group having 1 to 4 carbon atoms, and R ³ represents an alkyl group or alkoxy group having 1 to 4 carbon atoms.)

（式中、Ｒ¹、Ｒ²及びＲ³は、前記と同じである。）

(Wherein R ¹ , R ² and R ³ are the same as described above.)

[2] A process for producing a methyl (3-oxocyclopentyl) acetate derivative, wherein the cyclopentanone derivative represented by the general formula (III) obtained by the process of [1] is reacted with water.

  ADVANTAGE OF THE INVENTION According to this invention, the cyclopentanone derivative which can become an intermediate body of the methyl (3-oxocyclopentyl) acetate derivative useful as a fragrance | flavor raw material can be manufactured efficiently.

  The method for producing a cyclopentanone derivative represented by the general formula (III) according to the present invention includes a 2-cyclopentene represented by the general formula (I) in the presence of a solid base catalyst containing a phosphazene base or a guanidine base. A Michael addition reaction is performed between the -1-one derivative and the ester compound represented by the general formula (II).

[2-Cyclopenten-1-one derivative]
The 2-cyclopenten-1-one derivative used in the present invention is represented by the following general formula (I).

（式中、Ｒ¹は炭素数１〜１０の炭化水素基を示す。）

(In the formula, R ¹ represents a hydrocarbon group having 1 to 10 carbon atoms.)

The number of carbon atoms of the hydrocarbon group represented by R ¹ in the general formula (I) is ¹ to 8 from the viewpoint of the fragrance of the finally obtained methyl (3-oxocyclopentyl) acetate derivative and the reactivity of the Michael addition reaction. Preferably, 3-7 are more preferable, and 4-6 are still more preferable.
As the hydrocarbon group as R ¹ , an alkyl group, an alkenyl group, and an alkynyl group are preferable, and an alkyl group and an alkenyl group are more preferable from the viewpoint of the fragrance of the finally obtained methyl (3-oxocyclopentyl) acetate derivative. An alkyl group is more preferable.
Preferable examples of the alkyl group include a propyl group, an isopropyl group, a butyl group, a pentyl group, a hexyl group and the like. Among them, from the viewpoint of the fragrance of the finally obtained methyl (3-oxocyclopentyl) acetate derivative, n -A pentyl group is preferred.
Preferable examples of the alkenyl group include a propenyl group, a butenyl group, a pentenyl group, a hexenyl group, etc. Among them, a pentenyl group is preferable from the viewpoint of the fragrance of the finally obtained methyl (3-oxocyclopentyl) acetate derivative. .

[Ester compound]
The ester compound used in the present invention is represented by the following general formula (II).

（式中、Ｒ²は炭素数１〜４のアルキル基を示し、Ｒ³は炭素数１〜４のアルキル基又はアルコキシ基を示す。）

(In the formula, R ² represents an alkyl group having 1 to 4 carbon atoms, and R ³ represents an alkyl group or alkoxy group having 1 to 4 carbon atoms.)

Examples of the alkyl group having 1 to 4 carbon atoms as R ² include a methyl group, an ethyl group, a propyl group, an isopropyl group, and a butyl group, but the reactivity and the finally obtained methyl (3-oxocyclopentyl) acetate From the viewpoint of the fragrance of the derivative, a methyl group and an ethyl group are preferable, and a methyl group is more preferable.
As a C1-C4 alkyl group or alkoxy group which is R < ³ >, an alkoxy group is preferable from a reactive viewpoint. Specific examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, and a butoxy group. From the viewpoint of reactivity and fragrance of the methyl (3-oxocyclopentyl) acetate derivative finally obtained. Therefore, a methoxy group and an ethoxy group are preferable, and a methoxy group is more preferable.

[Solid base catalyst]
The solid base catalyst used in the present invention contains a phosphazene base or a guanidine base.
The reason why the cyclopentanone derivative represented by the general formula (III) can be efficiently obtained by using a solid base catalyst containing these bases is not clear, but is considered as follows. That is, phosphazene base and guanidine base are organic bases, which are strong because they are bonded to at least three nitrogen atoms with respect to the carbon atom or phosphorus atom, and one of them forms a double bond. Shows basicity. Therefore, in the presence of a solid base catalyst containing a phosphazene base or a guanidine base, a 2-cyclopenten-1-one derivative represented by the general formula (I) and an ester compound represented by the general formula (II) are mixed with Michael. When the addition reaction is performed, a strong organic base is present, so that the affinity with the substrate molecule is excellent, and the efficiency as a catalyst can be increased. Therefore, the cyclopentanone derivative represented by the general formula (III) is efficiently produced. It is considered to be obtained.

The solid base catalyst containing a phosphazene base or a guanidine base is preferably one in which the base is supported on a carrier.
As the carrier, organic polymer, silica, alumina, silica alumina, titania, zirconia, diatomaceous earth, activated carbon and the like can be used. If the carrier is used in excess, the content of the solid base catalyst is lowered and the catalytic activity is lowered. Therefore, the proportion of the carrier in the catalyst is preferably 50 to 90% by mass.
The shape of the solid base catalyst may be a powder or a molded one. Moreover, all the solid bases may have the same composition, or a combination of solid bases having different compositions may be used.

Among the above carriers, organic polymers are preferable. Since it is easy to adjust the shape of the organic polymer, by supporting the base on the organic polymer, the contact area is increased while maintaining the affinity with the substrate molecule, or the catalyst is separated by solid-liquid separation. Can be easily removed.
Examples of the organic polymer include polystyrene resins, such as ArgoPore (registered trademark) resin (aminomethyl polymer resin: P-aminomethylated polystyrene and 1% divinylbenzene copolymer).
In addition, a crosslinked resin is preferable from the viewpoint of preventing impurities from being mixed into the obtained cyclopentanone derivative. Examples of the crosslinked resin include crosslinked polystyrene, crosslinked polymethyl methacrylate, crospovidone (crosslinked polyvinyl pyrrolidone), crosslinked carboxymethyl starch sodium, and crosslinked carboxymethyl cellulose sodium. Among these, a crosslinked polystyrene resin is more preferable from the viewpoint of versatility and the like. Preferred examples of the crosslinked polystyrene resin include Jandajel (registered trademark) resin (polystyrene resin crosslinked with a crosslinking agent having a 1,4-butanediol structure).

<Phosphazene base>
The phosphazene base has a structure composed of one or more phosphazene units, and exhibits extremely strong basicity by delocalizing the cationic property of the conjugate acid over a wide range and stabilizing the resonance structure. The phosphazene base is not particularly limited as long as it has a desired basicity, and can be appropriately selected from known ones or those synthesized by applying known techniques. Examples include those described in Schwesinger R. et al., Liebigs Ann., 1055-1081 (1996); Schwab PFH et al., J. Org. Chem., 67, 443-449 (2002). .
Of these, the phosphazene base represented by the following formula (IV) is preferable.

In formula (IV), Z represents an alkyl group or an aryl group, and Y represents a dialkylamino group, a pyrrolidino group, a piperidino group, a morpholino group, a piperazino group, a trisdialkylaminophosphine imino group, or a trispyrrolidinophosphine imino group. Or an alkylenediamino group, an N-alkylalkylenediamino group, or an N, N′-dialkylalkylenediamino group in which two Ys are bonded by an alkylene group, each Y may be the same or different, and q is 1 An integer of ~ 3 is shown. The alkyl group or alkylene group is preferably one having 1 to 6 carbon atoms, more preferably 2 to 4 carbon atoms.
From the viewpoint of catalytic activity, Z is preferably an alkyl group having 1 to 6 carbon atoms, preferably 2 to 4 carbon atoms, Y is a dialkylamino group having an alkyl group having 1 to 6 carbon atoms, or two Y are carbon atoms. An alkylenediamino group bonded by an alkylene group of 1 to 3 atoms is preferable, and q is preferably 1 or 2.
Among the phosphazene bases, a particularly preferable commercially available product is 2-tert-butylimino-2-diethylamino-1,3-dimethylperhydro-1,3,2-diaza represented by the following formula (IV-1): P-BEMP (manufactured by Sigma-Aldrich Co., Ltd.) in which phospholine (hereinafter also referred to as “BEMP”) is supported on a polystyrene-based organic polymer is exemplified.

<Guanidine base>
As the guanidine base, a cyclic guanidine base represented by the following formula (V) is preferable.

In formula (V), X is N or C, and n and m independently represent an integer of 1 to 4.
From the viewpoint of catalytic activity, a bicyclic guanidine in which X is N and n and m are independently 1 or 2 is preferred.
Among these, the 1,3,4,6,6, 1,4,6,6, and Jandajel (registered trademark) resins, which are polystyrene resins crosslinked by a crosslinking agent having a 1,4-butanediol structure represented by the following formula (IV-1): Jandajel-TBD (Sigma Aldrich) represented by the following structural formula (IV-2) carrying 7,8-hexahydro-2H-pyrimido- [1,2-A] pyrimidine (hereinafter also referred to as “TBD”) Manufactured).

[Method for producing cyclopentanone derivative]
In the present invention, the process for producing a cyclopentanone derivative represented by the following general formula (III) comprises 2-cyclopentene represented by the above general formula (I) in the presence of a solid base catalyst containing a phosphazene base or a guanidine base. The -1-one derivative and the ester compound represented by the general formula (II) are subjected to a Michael addition reaction.
The Michael addition reaction is a reaction in which a nucleophile (an ester compound represented by the general formula (II)) is added to an α, β-unsaturated carbonyl compound.

（式中、Ｒ¹は炭素数１〜１０の炭化水素基を示し、Ｒ²は炭素数１〜４のアルキル基示し、Ｒ³は炭素数１〜４のアルキル基又はアルコキシ基を示す。）

(In the formula, R ¹ represents a hydrocarbon group having 1 to 10 carbon atoms, R ² represents an alkyl group having 1 to 4 carbon atoms, and R ³ represents an alkyl group or alkoxy group having 1 to 4 carbon atoms.)

In the present invention, the order of mixing the 2-cyclopenten-1-one derivative represented by the general formula (I), the ester compound represented by the general formula (II), and the solid base catalyst is not particularly limited. It is preferable that the solid base catalyst and the ester compound are mixed, and then the 2-cyclopenten-1-one derivative is dropped and reacted.
In the present invention, it is preferable to use a solvent in order to dissolve the substrate. The solvent is not particularly limited as long as it dissolves the substrate, but an alcohol having 1 to 3 carbon atoms is preferable, and methanol is more preferable.
This Michael addition reaction is performed, for example, in an atmosphere of an inert gas such as nitrogen or argon, usually at 0 to 60 ° C., preferably 0 to 20 ° C. for about 1 to 50 hours, preferably 4 to 40 hours. It is.
The proportion of the ester compound used relative to the 2-cyclopenten-1-one derivative (ester compound / 2-cyclopenten-1-one derivative) (molar ratio) is usually 1 to 10, preferably 1.1 to 2.5. Preferably it is 1.2-2.0. By using an ester compound in excess, the reaction can proceed efficiently.

The amount of the solid base catalyst used can be appropriately optimized depending on the reaction mode, conditions and the like.
In the case of a batch type, from the viewpoint of reactivity and economy, the amount of the catalyst is preferably 0.5 to 20% by mass with respect to the total amount of the 2-cyclopenten-1-one derivative, the ester compound, and the catalyst. The mass% is more preferable.
The solid base catalyst can be easily separated from the reaction product, and the catalyst can be recycled by omitting the neutralization step.
Examples of the method for separating the solid base catalyst after use include a sedimentation separation method and a filtration method, and can be appropriately selected according to the particle size and specific gravity of the solid catalyst. For example, when the particle size of the solid catalyst is large or the specific gravity is large, a sedimentation separation method by gravity is preferable. On the other hand, when the particle size of the solid catalyst is small or the specific gravity is small, it is separated into a filter cake and a filtrate by a centrifugal separation method or centrifugal filtration method using centrifugal force, or by a filter medium partition wall using pressure or reduced pressure. A filtration method is preferred.

[Method for producing methyl (3-oxocyclopentyl) acetate derivative]
The method for producing a methyl (3-oxocyclopentyl) acetate derivative in the present invention uses a cyclopentanone derivative represented by the general formula (III) obtained by the above-described method of the present invention as a raw material. This is a method of reacting a non-derivative with water.
In particular, when the ester compound is a malonic acid ester, water is preferably added in an amount of 1 to 3 moles relative to the cyclopentanone derivative, and the reaction is preferably carried out while dropping in the reaction system. The reaction temperature at this time is preferably 150 to 230 ° C, more preferably 180 to 220 ° C.
The methyl (3-oxocyclopentyl) acetate derivative thus obtained has a good yield and can reduce the purification load for obtaining high purity, and is excellent as a perfume material.

In the following examples and comparative examples, “%” is “% by mass” unless otherwise specified.
The product was quantified by an internal standard method by gas chromatography (GC) [GC measurement instrument (Agilent Technology, 6890N, column: DB-1 (30 m × 0.25 mm × 0.25 μm), GC conditions (oven : 100 ° C. → 5 ° C./min.→210° C. → 20 ° C./min.→280° C. (4.5 min. Hold) (total 30 min.), Carrier: He, flow rate: 1.6 mL / min., Inlet: 280 ° C., detector (FID): 280 ° C., injection volume: 1 μL, split: 100: 1), internal standard: undecane].

Example 1 (Production of dimethyl 2- (3-oxo-2-pentylcyclopentyl) malonate using solid base catalyst P-BEMP)
(1) Synthesis of 2-pentyl-2-cyclopenten-1-one (1-i) In a 6 m ³ reaction tank equipped with a dropping tank, 2241 kg (26.6 kmol) of cyclopentanone, 1007 kg of water, 11 kg of 48% NaOH Was cooled to 15 ° C. with stirring, and 985 kg (11.4 kmol) of valeraldehyde was added dropwise at the same temperature over 5 hours. After completion of dropping, the mixture was stirred at the same temperature for 1 hour. After the completion of the reaction, the reaction mixture was neutralized and excess cyclopentanone was recovered by distillation to obtain 1868 kg of a reaction completed product.
(1-ii) 2- (1-hydroxypentyl) -cyclopenta obtained by rectifying the reaction-finished product obtained in (1-i) above in a 300 ml four-necked flask equipped with a dehydrating tube Non-170 g (0.99 mol) and 8.5 g of TiO ₂ (spherical molded product, diameter 1.5 mm) were added, heated and mixed to 100 ° C. and 53 kPa, and reacted for 6 hours.
The solid acid catalyst in the reaction product was filtered to obtain 153 g of the filtration product. The 2-pentylidenecyclopentanone contained in this was 141 g (0.93 mol) (yield 93%).
(1-iii) The filtered product obtained in (1-ii) above was dissolved in 153 g of n-butanol, heated to 130 ° C., and then 14.5 g (0.15 mol) of 3-picoline and 35 at the same temperature. A mixture of 10.5 g (0.1 mol) of% hydrochloric acid was added dropwise over 30 minutes. After completion of dropping, the mixture was heated and stirred at the same temperature for 3.5 hours. After completion of the reaction, the reaction mixture was cooled to room temperature and neutralized with an aqueous sodium hydroxide solution, and the organic layer was analyzed. As a result, 118 g of 2-pentyl-2-cyclopenten-1-one was contained in the finished product. (Yield 83%).

(2) Production of dimethyl 2- (3-oxo-2-pentylcyclopentyl) malonate In a 50 ml glass receiver, 0.30 g of a solid base catalyst “P-BEMP” (manufactured by Sigma-Aldrich) containing phosphazene base 0.752 mmol), 1.52 g of methanol, and 4.96 g (0.0375 mol) of dimethyl malonate were added and cooled to 0 ° C. 3.80 g (purity 85%, 0.021 mol) of 2-pentyl-2-cyclopenten-1-one obtained in (1) above was added dropwise, and 101 kPa (ordinary) at 0 ° C. for 25 hours under a nitrogen atmosphere. The reaction was conducted with stirring under the condition of (pressure).
After completion of the reaction, the reaction product was quantified by GC. As a result, 5.49 g (0.019 mol) of dimethyl 2- (3-oxo-2-pentylcyclopentyl) malonate was produced.
In addition, the reaction product was centrifuged using a centrifuge at 2200 rpm for 5 minutes to precipitate a solid catalyst. Thereafter, the organic layer was recovered using a pipette, and methanol and unreacted dimethyl malonate were distilled off under reduced pressure to obtain dimethyl 2- (3-oxo-2-pentylcyclopentyl) malonate (yield 92%). . The results are shown in Table 1.

Example 2 (Confirmation of catalyst recyclability)
A reaction similar to that in Example 1 (2) was carried out for 29 hours except that the catalyst after the organic layer was recovered after centrifugation in Example 1 (2) was subjected to 29 hours. As a result, dimethyl 2- (3-oxo-2) was obtained. The yield of -pentylcyclopentyl) malonate was 91%.

Example 3 (Confirmation of catalyst recyclability; second time)
Except for using the catalyst recovered from the organic layer after centrifugation in Example 2, the same reaction as in Example 1 (2) was performed for 31 hours. As a result, dimethyl 2- (3-oxo-2-pentylcyclopentyl) was obtained. ) The yield of malonate was 67%.

Example 4 (Production of dimethyl 2- (3-oxo-2-pentylcyclopentyl) malonate using solid base catalyst Jandajel-TBD)
To a 50 ml glass receiver, 0.88 g (0.748 mmol) of Jandajel-TBD (Sigma Aldrich), 1.69 g of methanol and 4.96 g (0.0375 mol) of dimethyl malonate were added and cooled to 0 ° C. . 3.81 g (purity 85%, 0.021 mol) of 2-pentyl-2-cyclopenten-1-one obtained in Example (1) was added dropwise, and the mixture was added 101 kPa (29 kPa) at 0 ° C. for 29 hours in a nitrogen atmosphere. The reaction was carried out with stirring under the conditions of (normal pressure).
After completion of the reaction, the reaction product was quantified by GC. As a result, 4.69 g (0.017 mol) of dimethyl 2- (3-oxo-2-pentylcyclopentyl) malonate was produced.
Moreover, after centrifuging similarly to Example 1 and precipitating a solid catalyst, the organic layer was recovered, methanol and unreacted dimethyl malonate were distilled off under reduced pressure, and dimethyl 2- (3-oxo-2 -Pentylcyclopentyl) malonate was obtained (yield 75%). The results are shown in Table 1.

Comparative Example 1 (using potassium carbonate catalyst)
To a 50 ml glass receiver, 0.2 g of potassium carbonate, 1.52 g of methanol, and 4.96 g (0.0373 mol) of dimethyl malonate were added. 2.80 g (purity 85%, 0.021 mol) of 2-pentylcyclopenten-1-one synthesized in the same manner as in Example 1 was added dropwise, and the mixture was 101 kPa (normal pressure) at 0 ° C. for 5 hours under a nitrogen atmosphere. The reaction was carried out with stirring under the conditions.
After completion of the reaction, the reaction product was quantified by GC. As a result, 4.17 g (0.015 mol) of dimethyl 2- (3-oxo-2-pentylcyclopentyl) malonate was produced.
Moreover, after centrifuging similarly to Example 1 and precipitating a solid catalyst, the organic layer was recovered, methanol and unreacted dimethyl malonate were distilled off under reduced pressure, and dimethyl 2- (3-oxo-2 -Pentylcyclopentyl) malonate was obtained (yield 72%). The results are shown in Table 1.

Comparative Example 2 (Confirmation of recyclability of potassium carbonate catalyst)
Except for using the catalyst recovered from the organic layer after centrifugation, the same reaction as in Comparative Example 1 was carried out for 5 hours. As a result, the yield of dimethyl 2- (3-oxo-2-pentylcyclopentyl) malonate was 46%. there were.
Comparative Example 3 (Confirmation of recyclability of potassium carbonate catalyst; second time)
A reaction similar to that of Comparative Example 2 was carried out for 5 hours, except that the catalyst recovered from the organic layer after centrifugation was used instead of the catalyst after completion of the reaction of Comparative Example 5. As a result, dimethyl 2- (3-oxo-2 The yield of -pentylcyclopentyl) malonate was 6%.

Comparative Example 4 (using MgO catalyst)
To a 50 ml glass receiver, 0.19 g of magnesium oxide (manufactured by Kyowa Chemical Industry Co., Ltd., trade name: Kyowa Mag 150), 1.53 g of methanol, and 4.96 g (0.0375 mol) of dimethyl malonate were added. 3.82 g (purity 85%, 0.021 mol) of 2-pentyl-2-cyclopenten-1-one obtained in Example (1) was added dropwise, and 101 kPa (105 kPa) at 25 ° C. under a nitrogen atmosphere for 105 hours. The reaction was carried out with stirring under the conditions of (normal pressure).
After completion of the reaction, the reaction product was quantified by GC. As a result, 3.82 g of 2-pentylcyclopentene was recovered, and dimethyl 2- (3-oxo-2-pentylcyclopentyl) malonate was not produced. The results are shown in Table 1.

Comparative Example 5 (using hydrotalcite catalyst)
Hydrotalcite (manufactured by Kyowa Chemical Industry Co., Ltd., trade name: KW-1000) 0.19 g, methanol 1.52 g, and dimethyl malonate 4.95 g (0.0375 mol) were added to a 50 ml glass receiver. 3.80 g (purity 85%, 0.021 mol) of 2-pentyl-2-cyclopenten-1-one obtained in Example (1) was added dropwise and added under nitrogen atmosphere at 25 ° C. for 80 hours, 101 kPa ( The reaction was carried out with stirring under the conditions of (normal pressure).
After completion of the reaction, the reaction product was quantified by GC. As a result, 3.80 g of 2-pentylcyclopentene was recovered, and dimethyl 2- (3-oxo-2-pentylcyclopentyl) malonate was not produced. The results are shown in Table 1.

Comparative Example 6 (Using strongly basic anion exchange resin catalyst)
In a 50 ml glass receiver, 0.20 g of strongly basic anion exchange resin (manufactured by Organo Corporation, trade name: Amberlite IRA458RF, adjusted from CL-type to OH-type according to a conventional method), methanol 1. 52 g and 4.97 g (0.0376 mol) of dimethyl malonate were added. 3.80 g (purity 85%, 0.021 mol) of 2-pentylcyclopenten-1-one synthesized in the same manner as in Example 1 was added dropwise, and the reaction was performed at 101 kPa (normal pressure) at 25 ° C. for 31 hours under a nitrogen atmosphere. The reaction was carried out with stirring under the conditions.
After completion of the reaction, the reaction product was quantified by GC. As a result, 3.80 g of 2-pentylcyclopentene was recovered, and dimethyl 2- (3-oxo-2-pentylcyclopentyl) malonate was not produced. The results are shown in Table 1.

Comparative Example 7 (using sodium methoxide catalyst)
Under a nitrogen atmosphere, 208 g (1.56 mol) of dimethyl malonate (Aldrich) was dissolved in 63 g of anhydrous methanol (Aldrich), cooled to 0 ° C., and sodium methoxide (Wako Pure Chemical Industries, Ltd.). Manufactured, 30% methanol solution) 6.5 g (0.035 mol) was added. 183.48 g (purity 84%, 1.01 mol) of 2-pentyl-2-cyclopenten-1-one obtained in Example (1) was added dropwise and added under nitrogen atmosphere at 0 ° C. for 5 hours, 101 kPa ( The reaction was carried out with stirring under the conditions of (normal pressure).
After completion of the reaction, acetic acid is added to neutralize the catalyst until it becomes acidic, methanol and unreacted dimethyl malonate are distilled off under reduced pressure, and the organic layer is washed twice with water, and over magnesium sulfate. It was dried to obtain 283.48 g of dimethyl 2- (3-oxo-2-pentylcyclopentyl) malonate (yield 94%). The results are shown in Table 1.

From Table 1, according to the production methods of Examples 1 to 4, the Michael addition reaction between 2-cyclopenten-1-one and an ester compound proceeds efficiently, and a cyclopentanone derivative can be obtained in a high yield. At the same time, it can be seen that the purification operation is also efficient. In addition, Example 2 shows that sufficient catalytic activity is exhibited even when the solid base catalyst is reused.
Further, Examples 2 and 3 show that according to the method of the present invention, the neutralization step can be omitted and the catalyst can be recycled.
On the other hand, in the method using the solid base catalyst of Comparative Examples 1 to 3, the yield is low, and it can be seen that the yield is significantly reduced by recycling.
Furthermore, in the methods using the solid base catalysts of Comparative Examples 4 to 6, the target cyclopentanone derivative could not be obtained.
In the method of Comparative Example 7, the target cyclopentanone derivative could be obtained, but since it was a homogeneous catalyst, the purification operation was complicated and the production efficiency was lowered.

Example 5 (Production of methyl (3-oxocyclopentyl) acetate)
To a reaction apparatus equipped with a distillation distillation tube, 283.48 g of dimethyl 2- (3-oxo-2-pentylcyclopentyl) malonate obtained in Example 1 was added, heated to 215 ° C., and water was added dropwise. While distilling off the generated carbon dioxide and methanol, a drop reaction was carried out at 215 ° C. for 4 hours. After the reaction, 203.27 g of a crude product was obtained.
Methyl (3-oxo-2-pentylcyclopentyl) acetate (148.71 g) obtained by rectifying the crude product has a fruity and jasmine-like fragrance, and is an excellent fragrance material. there were.

  According to the production method of the present invention, the Michael addition reaction between the 2-cyclopenten-1-one derivative and the ester compound can be efficiently performed, the purification is efficient, and the catalyst can be reused. It is useful as a method for producing a cyclopentanone derivative that can be an intermediate of a methyl (3-oxocyclopentyl) acetate derivative useful as a perfume material.

Claims (9)

In the presence of a solid base catalyst containing a phosphazene base or a guanidine base, a 2-cyclopenten-1-one derivative represented by the general formula (I) and an ester compound represented by the general formula (II) are subjected to a Michael addition reaction. The manufacturing method of the cyclopentanone derivative represented by general formula (III).

(In the formula, R ¹ represents an alkyl group, an alkenyl group, or an alkynyl group having 3 to 8 carbon atoms.)

(In the formula, R ² represents an alkyl group having 1 to 4 carbon atoms, and R ³ represents an alkyl group or alkoxy group having 1 to 4 carbon atoms.)

(Wherein R ¹ , R ² and R ³ are the same as described above.)   The method for producing a cyclopentanone derivative according to claim 1, wherein the solid base catalyst is a phosphazene base or guanidine base supported on an organic polymer.   The method for producing a cyclopentanone derivative according to claim 2, wherein the organic polymer is a crosslinked polystyrene resin.   The cyclopentanone derivative according to any one of claims 1 to 3, wherein the phosphazene base is 2-tert-butylimino-2-diethylamino-1,3-dimethylperhydro-1,3,2-diazaphosphorin. Manufacturing method.   The production of a cyclopentanone derivative according to any one of claims 1 to 3, wherein the guanidine base is 1,3,4,6,7,8-hexahydro-2H-pyrimido- [1,2-A] pyrimidine. Method.   R ¹ Is a C3-C7 alkyl group, The manufacturing method of the cyclopentanone derivative in any one of Claims 1-5.   R ³ Is a C1-C4 alkoxy group, The manufacturing method of the cyclopentanone derivative in any one of Claims 1-6. The method for producing a cyclopentanone derivative according to any one of claims 1 to 7 , wherein R ¹ is an n-pentyl group. The method for producing a cyclopentanone derivative according to any one of claims 1 to 8 , wherein R ² is a methyl group and R ³ is a methoxy group.