JP2004352636A - Method for producing lactones or esters - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a lactone or an ester from a ketone readily in a high yield by using an inexpensively obtainable and readily handleable substance having no danger such as explosion, etc. <P>SOLUTION: The method for producing a lactone or an ester comprises treating a ketone with an organic acid and hydrogen peroxide in the presence of a metaborate. In the method, the metaborate, the organic acid and hydrogen peroxide are each a relatively inexpensive raw material and simply handleable. The amount of the metaborate used is normally an equimolar amount or less based on the raw material ketone and is a small amount of about 0.3-0.4 mol. Inevitably, since the amount of the metaborate thrown out is small, the method is advantageous with respect to treatment of solid waste. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

（式中、Ｒ^１及びＲ^２は、それぞれ独立してアルキル基又は置換基を有していてもよいアリール基を表す。また、Ｒ^１とＲ^２とでアルキル基で置換されていてもよいメチレン鎖を形成していてもよい。）
で示される化合物が挙げられる。
【０００８】
また、本発明の製造方法により得られるラクトン類又はエステル類は、例えば下記一般式［２］
【化４】

（式中、Ｒ^１及びＲ^２は前記と同じ。）
で示される化合物が挙げられる。
【０００９】
上記一般式［１］及び［２］において、Ｒ^１、Ｒ^２で表されるアルキル基としては、例えば炭素数１〜１５の直鎖状又は分岐状のアルキル基、好ましくは炭素数１〜１０の直鎖状又は分岐状のアルキル基が挙げられる。具体例としては、例えば、メチル基、エチル基、ｎ−プロピル基、イソプロピル基、ｎ−ブチル基、イソブチル基、ｓｅｃ−ブチル基、ｔｅｒｔ−ブチル基、ｎ−ペンチル基、イソペンチル基、ネオペンチル基、ｔｅｒｔ−ペンチル基、ｎ−ヘキシル基、ｎ−へプチル基、ｎ−オクチル基、ｎ−ノニル基、ｎ−デシル基等が挙げられる。
また、Ｒ^１、Ｒ^２で表される置換基を有していてもよいアリール基のアリール基としては、例えば、フェニル基、トリル基、キシリル基、ナフチル基、メチルナフチル基、ビフェニル基等が挙げられ、置換基としては、前記した如き直鎖状又は分岐状のアルキル基の他に、例えばメトキシ基、エトキシ基、ｎ−プロポキシ基、イソプロポキシ基、ｎ−ブトキシ基、ｔ−ブトキシ基等の炭素数１〜４のアルコキシ基、例えば、塩素、臭素、フッ素、沃素等のハロゲン原子等が挙げられる。これらの置換基は複数あってもよい。
Ｒ^１とＲ^２とで形成されるメチレン鎖としては、例えば炭素数２〜１５のメチレン鎖が挙げられ、具体例としては、例えば、エチレン基、トリメチレン基、テトラメチレン基、ペンタメチレン基、ヘプタメチレン基、ウンデカメチレン基等のポリメチレン基が挙げられる。これらポリメチレン基は前記した如き直鎖状又は分岐状のアルキル基で置換されていてもよい。
【００１０】
一般式［１］で示されるケトン類の具体例としては、例えば、２−ブタノン、４−メチル−２−ペンタノン、アセトフェノン、プロピオフェノン、２’−アセトナフトン、４−アセチルビフェニル、４’−メトキシアセトフェノン、４’−ｔｅｒｔ−ブトキシアセトフェノン、４’−クロロアセトフェノン等の非環状ケトン類、例えば、シクロペンタノン、シクロヘキサノン、シクロドデカノン等の無置換環状ケトン類、例えば、２−アルキルシクロペンタノン、２−アルキルシクロヘキサノン、２−アルキルシクロドデカノン、３−アルキルシクロペンタノン、３−アルキルシクロヘキサノン、３−アルキルシクロドデカノン等のアルキル置換光学活性又は非光学活性の環状ケトン類（アルキルとしては前記したようなアルキル基が挙げられる。）等が挙げられる。
【００１１】
本発明の製造方法においては、原料の一般式［１］で示されるケトン類が光学活性体であれば、反応により得られる一般式［２］で示される化合物もまた光学活性体である。
【００１２】
本発明の製造方法において、触媒的に用いられるメタホウ酸塩は、メタホウ酸塩の水和物又は無水物のどちらでも使用可能である。入手の容易性や価格等の点から、水和物を用いることが好ましいが、無水物、或いは無水物と水和物との混合物でも勿論支障なく反応は進行する。
メタホウ酸塩の具体例としては、メタホウ酸ナトリウム、メタホウ酸リチウム、メタホウ酸カリウム、メタホウ酸カルシウム等の水和物又は無水物が挙げられるが、メタホウ酸ナトリウムの水和物又は無水物が好ましい。メタホウ酸塩の使用量は、原料のケトン類に対し、通常０．１〜０．８倍モル、好ましくは０．２〜０．６倍モル、より好ましくは０．３〜０．４倍モルである。
【００１３】
本発明の製造方法において、酸化剤成分の１つとして用いられる有機酸としては、例えば、無置換又はハロゲン原子で置換された脂肪族カルボン酸等が好ましいものとして挙げられる。
このような脂肪族カルボン酸の具体例としては、例えば、酢酸、蟻酸、トリフルオロ酢酸等が挙げられるが、操作性、経済性等の点から酢酸が特に好ましい。
有機酸の使用量は、特に限定されるものではないが、原料のケトン類に対し、通常５〜２０倍モル、好ましくは５〜１０倍モルである。なお、有機酸が液体の場合には、反応溶媒を兼ねることも可能なので、そのような場合は有機酸の使用量をその分多く使用することも任意である。
【００１４】
酸化剤の成分の他の１つとして用いられる過酸化水素の使用量は、原料のケトン類に対して、通常１．１〜３．０倍モル、好ましくは１．２〜２．０倍モル、より好ましくは１．２〜１．５倍モルである。
過酸化水素は、特にこれに限定されると言うわけではないが、通常３０％前後の水溶液として用いられる。
【００１５】
反応は、通常、溶液又はスラリー状態で行われる。
酸化剤成分の１つとして用いられる有機酸が固体の場合、或いは液体であってもその使用量をコスト或いはその他の理由（廃液処理等）により必要最小量に抑えたい場合等は、必要に応じて適当な溶媒を反応溶媒として用いて反応を行っても良い。そのような溶媒としては、本発明に係る反応に関与しない溶媒であればどのような溶媒でも良いが、例えば、ベンゼン、トルエン等の芳香族炭化水素類、例えば、メタノール、エタノール等の低級アルコール類、例えば、塩化メチレン、１，２−ジクロロエタン等のハロゲン化炭化水素類等が挙げられる。中でも、水と混和するメタノール、エタノール等の低級アルコール類が好ましい。
反応温度は、特に限定されるものではないが、通常５０〜９０℃、好ましくは７０〜８０℃である。反応温度が低いと反応速度が遅く、反応温度が高過ぎると好ましくない副反応が起こる可能性がある。反応時間は反応温度その他の反応条件により自ずから異なるが、通常４時間〜１０時間程度である。
反応終了後は、必要に応じて、過剰の過酸化物を亜硫酸水素ナトリウムや亜硫酸ナトリウム等の還元剤で処理して除いた後、溶媒の留去、生成物の抽出、再沈殿等の通常の後処理操作、更には、要すれは蒸留、再結晶、カラム処理等の精製操作を行うことにより、ラクトン類又はエステル類を得ることができる。
【００１６】
【実施例】
以下、実施例により本発明を更に具体的に説明するが、本発明はこれら実施例により何ら限定されるものではない。
【００１７】
実施例１ ２−ｎ−ヘキシルシクロペンタノンからのδ−ｎ−ヘキシル−δ−バレロラクトンの合成
２００ｍｌの四頚フラスコに、２−ｎ−ヘキシルシクロペンタノン２０ｇ（０．１２ｍｏｌ）、酢酸５３．５ｇ（０．８９ｍｏｌ）及びメタホウ酸ナトリウム２水和物３．６２ｇ（０．０３６ｍｏｌ）を仕込み、窒素気流下で攪拌しながら、７０℃に加温した。 続いて、３０％過酸化水素水溶液１４．８ｇ（０．１３ｍｏｌ）を６分の１量（２．４６ｇ）ずつ３０分間隔で撹拌下に滴下した。滴下後、反応温度を７０℃に保ちながら、合計５時間撹拌、反応させた。反応後、反応液をガスクロマトグラフィーにより分析し、原料である２−ｎ−ヘキシルシクロペンタノンの転化率と生成物であるδ−ｎ−ヘキシル−δ−バレロラクトンの選択率を求めた。
２−ｎ−ヘキシルシクロペンタノンの転化率は８２％で、δ−ｎ−ヘキシル−δ−バレロラクトンの選択率は９５％であった。
【００１８】
実施例２
３０％過酸化水素水溶液の使用量を２０．２ｇ（０．１８ｍｏｌ）に換えた以外は実施例１と同様にして反応を行ない、同様にして分析を行った結果、反応５時間後の２−ｎ−ヘキシルシクロペンタノンの転化率は９０％で、δ−ｎ−ヘキシル−δ−バレロラクトンの選択率は９６％であった。
【００１９】
実施例３
メタホウ酸ナトリウム２水和物の使用量を７．２４ｇ（０．０７２ｍｏｌ）とし、３０％過酸化水素水溶液を１時間間隔で３分の１の量（４．９３ｇ）ずつ添加する方法に変更した以外は実施例１と同様にして反応を行ない、同様にして分析を行った結果、反応５時間後の２−ｎ−ヘキシルシクロペンタノンの転化率は８４％で、δ−ｎ−ヘキシル−δ−バレロラクトンの選択率は９５％であった。
【００２０】
比較例１
メタホウ酸ナトリウム２水和物を使用しないこと以外は、実施例１と同様にして反応を行ない、同様にして分析を行った結果、反応５時間後の２−ｎ−ヘキシルシクロペンタノンの転化率は３５％で、δ−ｎ−ヘキシル−δ−バレロラクトンの選択率は３０％であった。
実施例１〜３及び比較例１の結果を表１にまとめて示す。
【００２１】
【表１】

【００２２】
上記表１の結果から明らかなように、メタホウ酸ナトリウムを原料ケトンに対し０．３〜０．６倍モル添加、併用することにより、有機酸と過酸化水素による酸化反応が顕著に進行し、且つ反応生成物であるδ−ｎ−ヘキシル−δ−バレロラクトンの選択率が高くなることが判る。
【００２３】
実施例４
３０％過酸化水素水溶液を３時間を要して滴下する方法に変更し、且つ反応温度を６０℃に下げたこと以外は実施例１と同様にして反応を行ない、同様にして分析を行った結果、反応５時間後の２−ｎ−ヘキシルシクロペンタノンの転化率は６４％で、δ−ｎ−ヘキシル−δ−バレロラクトンの選択率は９８％であった。この結果からも反応温度が低いと、反応に時間を要することが判る。
【００２４】
【発明の効果】
本発明は、各種ケトン類からラクトン類又はエステル類を容易に且つ収率良く製造する方法を提供するものである。本発明で使用するメタホウ酸塩、有機酸及び過酸化水素は、何れも比較的安価な原料であって、且つ取り扱いが簡便であり、しかもメタホウ酸塩の使用量は、通常原料ケトン類に対して等モル以下の、０．３〜０．４倍モル程度と少ない量で良く、必然的に廃棄するメタホウ酸塩の量も少ないので、廃固体処理の面からも大きな利点がある。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for producing lactones or esters from ketones. Lactones or esters are widely used as fine chemical raw materials or fragrances.
[0002]
[Prior art]
As a method for producing lactones or esters by oxidizing ketones, a production method by a so-called Baeyer-Villiger oxidation reaction in which an oxidizing agent is allowed to act on a corresponding cyclic or acyclic ketone is well known. I have.
As a conventional oxidizing agent, organic peracids such as peracetic acid and m-chloroperbenzoic acid are often used. However, peracetic acid has a risk of explosion and ignition, and m-chloroperbenzoic acid is used. There are few known products that combine safety and economy, such as high price because they are not manufactured industrially.
On the other hand, a Bayer-Villiger oxidation reaction using sodium perborate as an oxidizing agent other than the organic peracid is also known (for example, see Patent Document 1). Sodium perborate is chemically stable, is an industrially produced oxidizing agent, and is estimated to have high safety and economy. However, in the above-mentioned method, since sodium perborate is required in an equivalent amount or more with respect to the ketones (usually, about 1.5 times equivalent is used), the amount of sodium borate to be discarded increases, which is environmentally unfavorable.
[0003]
[Patent Document 1]
US Pat. No. 4,988,825
[Problems to be solved by the invention]
Therefore, an object of the present invention is to provide a method for producing lactones or esters from ketones easily and in good yield using a substance which can be obtained at low cost, has no danger of explosion and the like, and is easy to handle. Is to do.
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present inventors have conducted intensive studies, and as a result, took up a combination of hydrogen peroxide and an organic acid as an oxidizing agent, and reacted them with ketones in the presence of metaborate. The present inventors have found that lactones or esters can be produced from cyclic or acyclic ketones easily, safely and inexpensively, and have completed the present invention.
[0006]
That is, the present invention relates to a method for producing a lactone or an ester, wherein an organic acid and hydrogen peroxide are allowed to act on a ketone in the presence of a metaborate.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
The ketones used in the production method of the present invention include, for example, the following general formula [1]
Embedded image

(Wherein, R ¹ and R ² each independently represent an alkyl group or an aryl group which may have a substituent. Further, R ¹ and R ² may be substituted with an alkyl group. (It may form a methylene chain.)
The compound shown by these is mentioned.
[0008]
Lactones or esters obtained by the production method of the present invention include, for example, the following general formula [2]
Embedded image

(In the formula, R ¹ and R ² are the same as described above.)
The compound shown by these is mentioned.
[0009]
In the general formulas [1] and [2], examples of the alkyl group represented by R ¹ and R ² include a linear or branched alkyl group having 1 to 15 carbon atoms, and preferably 1 to 10 carbon atoms. A linear or branched alkyl group. Specific examples include, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, Examples include a tert-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, and an n-decyl group.
Examples of the aryl group of the optionally substituted aryl group represented by R ¹ and R ² include a phenyl group, a tolyl group, a xylyl group, a naphthyl group, a methylnaphthyl group, a biphenyl group and the like. Examples of the substituent include, in addition to the above-mentioned linear or branched alkyl group, for example, a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a t-butoxy group, and the like. And a halogen atom such as chlorine, bromine, fluorine and iodine. These substituents may be plural.
Examples of the methylene chain formed by R ¹ and R ² include a methylene chain having 2 to 15 carbon atoms. Specific examples include, for example, an ethylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, and a heptamethyl group. And polymethylene groups such as methylene group and undecamethylene group. These polymethylene groups may be substituted with a linear or branched alkyl group as described above.
[0010]
Specific examples of the ketones represented by the general formula [1] include, for example, 2-butanone, 4-methyl-2-pentanone, acetophenone, propiophenone, 2′-acetonaphthone, 4-acetylbiphenyl, 4′-methoxy Non-cyclic ketones such as acetophenone, 4'-tert-butoxyacetophenone, 4'-chloroacetophenone, for example, unsubstituted cyclic ketones such as cyclopentanone, cyclohexanone and cyclododecanone, for example, 2-alkylcyclopentanone, Alkyl-substituted optically or non-optically active cyclic ketones such as 2-alkylcyclohexanone, 2-alkylcyclododecanone, 3-alkylcyclopentanone, 3-alkylcyclohexanone and 3-alkylcyclododecanone (the alkyl is as described above) Such an alkyl group is mentioned. ) And the like.
[0011]
In the production method of the present invention, when the ketone represented by the general formula [1] as a raw material is an optically active substance, the compound represented by the general formula [2] obtained by the reaction is also an optically active substance.
[0012]
In the production method of the present invention, the metaborate used as a catalyst can be either a hydrate or an anhydride of metaborate. It is preferable to use a hydrate from the viewpoint of availability, price, and the like, but the reaction proceeds without any problem even with an anhydride or a mixture of an anhydride and a hydrate.
Specific examples of the metaborate include hydrates and anhydrides such as sodium metaborate, lithium metaborate, potassium metaborate, and calcium metaborate, and hydrates or anhydrides of sodium metaborate are preferable. The amount of the metaborate used is usually 0.1 to 0.8 times mol, preferably 0.2 to 0.6 times mol, more preferably 0.3 to 0.4 times mol, based on the raw material ketones. It is.
[0013]
In the production method of the present invention, as the organic acid used as one of the oxidizing agent components, for example, aliphatic carboxylic acids which are unsubstituted or substituted with a halogen atom and the like are preferred.
Specific examples of such an aliphatic carboxylic acid include, for example, acetic acid, formic acid, trifluoroacetic acid and the like, and acetic acid is particularly preferred from the viewpoint of operability, economy and the like.
The amount of the organic acid to be used is not particularly limited, but is usually 5 to 20 times, preferably 5 to 10 times the mol of the starting ketones. When the organic acid is a liquid, it can also serve as a reaction solvent. In such a case, it is optional to use a larger amount of the organic acid.
[0014]
The amount of hydrogen peroxide used as another one of the components of the oxidizing agent is usually 1.1 to 3.0 times mol, preferably 1.2 to 2.0 times mol with respect to the raw material ketones. And more preferably 1.2 to 1.5 moles.
Although hydrogen peroxide is not particularly limited to this, it is usually used as an aqueous solution of about 30%.
[0015]
The reaction is usually performed in a solution or slurry state.
If the organic acid used as one of the oxidizer components is a solid, or if it is a liquid and the amount of use is desired to be reduced to the necessary minimum amount due to cost or other reasons (such as waste liquid treatment), if necessary, The reaction may be carried out using an appropriate solvent as a reaction solvent. As such a solvent, any solvent may be used as long as it does not participate in the reaction according to the present invention.Examples include aromatic hydrocarbons such as benzene and toluene, and lower alcohols such as methanol and ethanol. Examples thereof include halogenated hydrocarbons such as methylene chloride and 1,2-dichloroethane. Among them, lower alcohols such as methanol and ethanol that are miscible with water are preferred.
The reaction temperature is not particularly limited, but is usually 50 to 90 ° C, preferably 70 to 80 ° C. When the reaction temperature is low, the reaction rate is low, and when the reaction temperature is too high, undesirable side reactions may occur. The reaction time naturally varies depending on the reaction temperature and other reaction conditions, but is usually about 4 hours to 10 hours.
After completion of the reaction, if necessary, excess peroxide is treated with a reducing agent such as sodium hydrogen sulfite or sodium sulfite to remove the solvent, and then the solvent is distilled off, and the product is extracted and re-precipitated. Lactones or esters can be obtained by performing post-treatment operations and, more importantly, purification operations such as distillation, recrystallization, and column treatment.
[0016]
【Example】
Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.
[0017]
Example 1 Synthesis of δ-n-hexyl-δ-valerolactone from 2-n-hexylcyclopentanone In a 200 ml four-necked flask, 20 g (0.12 mol) of 2-n-hexylcyclopentanone, acetic acid 53. 5 g (0.89 mol) and 3.62 g (0.036 mol) of sodium metaborate dihydrate were charged and heated to 70 ° C. while stirring under a nitrogen stream. Subsequently, 14.8 g (0.13 mol) of a 30% aqueous hydrogen peroxide solution was added dropwise with stirring at an interval of 30 minutes for each 1/6 amount (2.46 g). After the dropwise addition, the mixture was stirred and reacted for a total of 5 hours while maintaining the reaction temperature at 70 ° C. After the reaction, the reaction solution was analyzed by gas chromatography to determine the conversion of 2-n-hexylcyclopentanone as a raw material and the selectivity of δ-n-hexyl-δ-valerolactone as a product.
The conversion of 2-n-hexylcyclopentanone was 82%, and the selectivity for δ-n-hexyl-δ-valerolactone was 95%.
[0018]
Example 2
The reaction was carried out in the same manner as in Example 1 except that the amount of the 30% aqueous hydrogen peroxide solution was changed to 20.2 g (0.18 mol), and the analysis was conducted in the same manner. The conversion of n-hexylcyclopentanone was 90%, and the selectivity for δ-n-hexyl-δ-valerolactone was 96%.
[0019]
Example 3
The amount of sodium metaborate dihydrate used was 7.24 g (0.072 mol), and the method was changed to a method in which a 30% aqueous hydrogen peroxide solution was added in one-third intervals (4.93 g) at hourly intervals. The reaction was conducted in the same manner as in Example 1 except for the above, and the analysis was conducted in the same manner. As a result, the conversion of 2-n-hexylcyclopentanone after 5 hours from the reaction was 84%, and δ-n-hexyl-δ Valerolactone selectivity was 95%.
[0020]
Comparative Example 1
The reaction was conducted in the same manner as in Example 1 except that sodium metaborate dihydrate was not used, and the analysis was conducted in the same manner. As a result, the conversion of 2-n-hexylcyclopentanone after 5 hours of the reaction was determined. Was 35%, and the selectivity for δ-n-hexyl-δ-valerolactone was 30%.
Table 1 summarizes the results of Examples 1 to 3 and Comparative Example 1.
[0021]
[Table 1]

[0022]
As is clear from the results in Table 1, the addition of sodium metaborate in an amount of 0.3 to 0.6 times the amount of the starting ketone, and the combined use thereof, significantly promoted the oxidation reaction between the organic acid and hydrogen peroxide, And it turns out that the selectivity of (delta) -n-hexyl- (delta) -valerolactone which is a reaction product becomes high.
[0023]
Example 4
The reaction was carried out in the same manner as in Example 1 except that the method was changed to a method in which a 30% aqueous hydrogen peroxide solution was added dropwise over 3 hours, and the reaction temperature was lowered to 60 ° C., and the analysis was carried out in the same manner. As a result, the conversion of 2-n-hexylcyclopentanone after 5 hours of the reaction was 64%, and the selectivity for δ-n-hexyl-δ-valerolactone was 98%. From this result, it can be seen that when the reaction temperature is low, the reaction requires time.
[0024]
【The invention's effect】
The present invention provides a method for easily producing lactones or esters from various ketones in good yield. The metaborate, organic acid and hydrogen peroxide used in the present invention are all relatively inexpensive raw materials, and are easy to handle, and the amount of metaborate used is usually based on the amount of the starting ketones. Since the amount of the metaborate to be discarded is as small as about 0.3 to 0.4 times the equimolar or less, and the amount of the metaborate to be discarded is inevitably small, there is a great advantage in terms of waste solid treatment.

Claims (14)

A method for producing lactones or esters, wherein an organic acid and hydrogen peroxide are allowed to act on ketones in the presence of a metaborate. The ketone is represented by the following general formula [1]

(Wherein, R ¹ and R ² each independently represent an alkyl group or an aryl group which may have a substituent. Further, R ¹ and R ² may be substituted with an alkyl group. (It may form a methylene chain.)
Wherein the lactones or esters obtained by the reaction are represented by the following general formula [2]:

(In the formula, R ¹ and R ² are the same as described above.)
The production method according to claim 1, which is a compound represented by the formula: The method according to claim 1 or 2, wherein the metaborate is used in an amount of 0.1 to 0.8 times the mol of the starting ketones. The production method according to claim 1 or 2, wherein the metaborate is used in an amount of 0.2 to 0.6 times the mol of the starting ketones. The production method according to claim 1 or 2, wherein the metaborate is used in an amount of 0.3 to 0.4 times the mol of the starting ketones. The method according to any one of claims 1 to 5, wherein the metaborate is sodium metaborate dihydrate. The process according to any one of claims 1 to 6, wherein the reaction is carried out using an organic acid in an amount of 5 to 20 times the amount of the starting ketones. The process according to any one of claims 1 to 6, wherein the reaction is carried out using an organic acid in an amount of 5 to 10 times the amount of the starting ketones. The method according to claim 1, wherein the organic acid is acetic acid. The method according to any one of claims 1 to 9, wherein the reaction is carried out using 1.1 to 3.0 times the molar amount of hydrogen peroxide based on the starting ketones. The method according to any one of claims 1 to 9, wherein the reaction is carried out using 1.2 to 2.0 moles of hydrogen peroxide based on the starting ketones. The method according to any one of claims 1 to 9, wherein the reaction is carried out using 1.2 to 1.5 times mol of hydrogen peroxide to the starting ketones. The method according to any one of claims 1 to 12, wherein the ketone is a 5- or 6-membered cyclic ketone substituted with an alkyl group. The production method according to any one of claims 1 to 13, wherein the raw material ketone is an optically active cyclic ketone, and the obtained lactone is an optically active lactone.