JPH04275282A - Production of gamma-lactone - Google Patents

Abstract

PURPOSE:To produce the subject high-purity gamma-lactones excellent in flavor and useful for foods, etc., in a high yield by reacting a specified alcohol with a specified alkenoic acid ester under heating in the presence of an organic peroxide and a nitrogen-containing compound. CONSTITUTION:An alcohol represented by formula I (R1 is H or 1-15C alkyl; R2 is H, methyl or ethyl; R1, together with R2, forms butylene or pentylene) is reacted with a 2-alkenoic acid ester shown by formula II (R3 is H or 1-15C alkyl; R4 and R5 are H or methyl; R6 is 1-8C alkyl) under heating in the presence of an organic peroxide such as 1-bis-(t-butylperoxy)cyclohexane and a nitrogen-containing compound such as diethylamine, thus giving the objective gamma-lactone of formula III.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is directed to γ-pentyl, which has a fruit-like, peach-like, butter-like, milk-like aroma, and has been used as a compound flavoring material for food and cosmetics. γ-lactone, γ-hexyl-γ-lactone, γ-heptyl-γ-lactone, γ-octyl-
The following formula (1) including γ-lactone etc.

0002

[C4]

In the formula, R1, R2, R3, R4 and R5
relates to a novel method for producing γ-lactones having the above meaning.

0004

[Prior Art] Several methods have been known to date for the production of γ-lactones represented by the above formula (1). For example, acrylic ester and primary alcohol are
A method for producing γ-alkyl-γ-lactone by heating reaction in the presence of butyl peroxide and phosphate and/or sulfate (Japanese Unexamined Patent Publication No. 1983-95058),
Furthermore, a method for synthesizing γ-alkyl-γ-lactone by reacting an acrylic ester and a primary alcohol in the presence of an organic peroxide and a mineral acid and/or an organic acid (Japanese Patent Application Laid-open No.
5-133371) and the like have been proposed.

[0005]

[Problems to be Solved by the Invention] However, in the conventionally proposed method of carrying out the reaction in the presence of phosphates, sulfates, mineral acids, and organic acids, side reaction products are produced to the extent that they affect the reaction yield. Because of this, the yield is not necessarily satisfactory, and the processing operations after the reaction is complicated. Highly desired.

[0006]

[Means for Solving the Problems] The present inventors have conducted extensive research in order to establish a new manufacturing method that is industrially advantageous and can solve the above-mentioned problems. As a result, by performing a reaction between a certain alcohol and a specific 2-alkenoic acid ester in the presence of an organic peroxide and a nitrogen-containing base, the γ-lactone represented by the formula (1) can be produced. It has been found that the following compounds can be synthesized in unexpectedly good yields, with good purity, and with almost no side reaction products.

Thus, according to the present invention, the formula (1 ) is provided. The method for producing the compound of formula (1) of the present invention can be expressed as follows using a reaction formula.

[0008]

[C5]

In the formula, R1, R2, R3, R4 and R5
has the above meaning, according to the above reaction formula A, formula (1)
The method for producing the compound will be explained in detail.

The compound of formula (1) of the present invention can be synthesized from the compounds of formula (2) and (3) by heating the reaction in the presence of an organic peroxide and a nitrogen-containing compound. be able to.

The compound of formula (2) used in the present invention is an alcohol including primary and secondary alcohols, which are inexpensive and easily available as commercial products. Specific compounds of primary alcohols include methanol, ethanol, propanol,
Isopropanol, butanol, isobutanol, pentanol, isopentanol, 2-methylbutanol,
Hexanol, 2-methylpentanol, heptanol, octanol, 2-ethylhexanol, nonanol, 3,5,5-trimethylhexanol, decanol,
Undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol, etc.; Specific examples of secondary alcohols include isopropanol, butan-2-ol, pentane-2-ol, etc.
ol, pentan-3-ol, hexan-2-ol, heptane-2-ol, octan-2-ol, nonan-2-ol, decan-2-ol, dodecane-2-ol
Examples include ol, cyclopentanol, cyclohexanol, and the like.

[0012] The amount of these alcohols used is determined by the formula (3)
It is preferable to use the compound in excess with respect to the compound of formula (3).
) can be exemplified in an amount of 1 mol or more, more preferably about 5 mol to 20 mol, per 1 mol of the compound.

The 2-alkenoic acid esters of formula (3) used in the present invention are also easily available as commercial products.
It can be represented as an ester of a C1-C8 chain alcohol and a 2-alkenoic acid. As the chain alcohol,
For example, methanol, ethanol, propanol, isopropanol, butanol, isobutanol, pentanol, isopentanol, hexanol, heptanol,
Specific examples of 2-alkenoic acids include acrylic acid, methacrylic acid, crotonic acid, senecioic acid, tiglic acid, angelic acid, 2-pentenoic acid, 2-methyl-2- Pentenoic acid, 4-methyl-2-pentenoic acid, 2-hexenoic acid, 2-
Examples include heptenoic acid, 2-octenoic acid, 2-nonenoic acid, 2-decenoic acid, 2-dodecenoic acid, 2-tetradecenoic acid, 2-hexadecenoic acid, and 2-octadecenoic acid.

[0014] The organic peroxides used in the present invention include:
For example, 1,1-bis-(t-butylperoxy)cyclohexane (hereinafter referred to as "BBPC"), benzoyl peroxide (hereinafter referred to as "BPO"), di-t-
Butyl peroxide (hereinafter referred to as "DBPO"),
Methyl ethyl ketone peroxide (hereinafter referred to as "MEKP"), t-butyl peroxyacetate (hereinafter referred to as "MEKP")
1,1
-bis-(t-butylperoxy)3,3,5-trimethylcyclohexane (hereinafter referred to as "BBTC"),
2,2-bis-(t-butylperoxy)butane (hereinafter referred to as "BBPB"), t-butylperoxyisopropyl carbonate (hereinafter referred to as "BPIC")
etc. can be mentioned.

Although the amount of these organic peroxides used is not strictly limited, in general, compound 1 of formula (3)
For example, about 1 mol% to about 50 mol%,
Preferably, it can be about 5 mol% to about 30 mol%. If the amount of the organic peroxide used is less than 1 mol%, the reaction yield of the compound of formula (1) will decrease, and even if it is used more than 50 mol%, no improvement in the yield can be expected, and on the contrary, the This is not preferred because the reaction products increase.

Specific examples of nitrogen-containing compounds used in this reaction include diethylamine, diisopropylamine, di-n-propylamine, dibutylamine,
Secondary amines such as dihexylamine, dioctylamine, pyrrolidine, morpholine, piperidine; Tertiary amines such as pyridine, triethylamine, tripropylamine, tributylamine, trihexylamine, trioctylamine; the above secondary amines and quaternary ammonium salts such as hydrochlorides, hydrobromides, sulfates, phosphates, acetates of tertiary amines, trimethylbenzylammonium hydroxide, trimethylbenzylammonium chloride, trimethylbenzylammonium bromide, etc. can be exemplified.

The amount of these nitrogen-containing bases to be used is also not strictly limited; for example, about 0.5 to about 10% by weight, preferably about 1 to about 5% by weight, based on the compound of formula (3). % can be shown.

[0018] The reaction temperature of the above reaction is preferably higher than the temperature at which the organic peroxide decomposes, and such a temperature may vary depending on the type of organic peroxide used, but is, for example, about 50°C or higher. , preferably about 100°C to about 1
80°C can be mentioned. If the reaction temperature is lower than the decomposition temperature of the organic peroxide, the progress of the reaction will be slow and the yield will be extremely poor, and if the reaction temperature is higher than the decomposition temperature than necessary, the yield will also decrease, which is not preferable.

The form of the reaction carried out under such temperature conditions varies depending on the type of alcohol of formula (2) used in the reaction. For example, in the case of an alcohol having a boiling point higher than the decomposition temperature of the organic peroxide. can carry out the reaction under atmospheric pressure conditions. Further, when using an alcohol having a boiling point below the decomposition temperature of the organic peroxide, it is preferable to carry out the reaction under closed pressurized conditions such as in an autoclave.

The reaction time for this reaction varies depending on the reaction temperature and can be selected as appropriate, for example from about 2 hours to
A preferable range is about 20 hours. Furthermore, the above reaction can also be carried out in an organic solvent. Examples of the solvent include saturated hydrocarbons such as decalin, decane, and dodecane, and the amount used is, for example, about 1 to about 20 times the weight of the compound of formula (2). can. After the reaction is completed, the compound of formula (1) can be produced with good purity and yield by separating and purifying using means such as extraction with an organic solvent, distillation, and column chromatography.

Equation (1) that can be obtained in this way
Specific examples of compounds include γ-butyrolactone, γ-methyl-γ-lactone, γ-ethyl-γ-lactone, γ-propyl-γ-lactone, γ-isopropyl-
γ-lactone, γ-butyl-γ-lactone, γ-isobutyl-γ-lactone, γ-pentyl-γ-lactone, γ
-Isopentyl-γ-lactone, γ-hexyl-γ-lactone, γ-heptyl-γ-lactone, γ-octyl-
γ-lactone, γ-nonyl-γ-lactone, γ-decyl-γ-lactone, γ-dodecyl-γ-lactone, γ-tetradecyl-γ-lactone, γ-(2-methylpropyl)-γ-lactone, γ -(1-methylbutyl)-γ-lactone, γ-(1-ethylpentyl)-γ-lactone,
Monosubstituted γ-lactones such as γ-(2,4,4-trimethylpentyl)-γ-lactone; α-methyl-γ-pentyl-γ-lactone, α-methyl-γ-heptyl-
γ-lactone, β-methyl-γ-propyl-γ-lactone, β-methyl-γ-butyl-γ-lactone, β-methyl-γ-pentyl-γ-lactone, β-methyl-γ-heptyl-γ- Lactone, β-ethyl-γ-pentyl-γ
Disubstituted γ-lactones such as -lactone, β-propyl-γ-pentyl-γ-lactone; α,β-dimethyl-γ
-pentyl-γ-lactone, α,β-dimethyl-γ-hexyl-γ-lactone, α,β-dimethyl-γ-heptyl-γ-lactone, β,β-dimethyl-γ-pentyl-
γ-lactone, β,β-dimethyl-γ-heptyl-γ-
Lactone, α-methyl-β-ethyl-γ-pentyl-γ
-lactone, α-methyl-β-ethyl-γ-heptyl-
Tri-substituted γ-lactones such as γ-lactone; α, β,
γ-Trimethyl-γ-butyl-γ-lactone, α, β,
γ-trimethyl-γ-hexyl-γ-lactone, β, β
, γ-trimethyl-γ-propyl-γ-lactone; 1-oxaspiro (4.4
) Nonan-2-one, spiro-γ-lactones such as 1-oxaspiro(5.4)decane-2-one, and the like can be preferably exemplified.

Next, the present invention will be explained in more detail with reference to Examples.

[0023]

[Example 1] Synthesis of β-methyl-γ-propyl-γ-lactone 444 g of butanol (6
．． 0 mol), 60 g (0.6 mol) of methyl crotonate,
1.2 g of butylamine and 11.1 g (0.03 mol) of 1,1-bis-t-butylperoxycyclohexane
After purging the inside of the autoclave with nitrogen, heat gently while stirring. After the temperature inside the autoclave rose to 140° C. to 150° C. (inner pressure 3 Kg/cm 2 ), the reaction was further continued at the same temperature for 1 hour. After the reaction was completed, unreacted butanol was collected under reduced pressure from the cooled and taken out reaction product to obtain 51.9 g of a residue. The obtained residue was distilled to obtain 100% pure β-methyl-γ-propyl-γ.
-26.5 g (yield 31.2%) of lactone was obtained.

[0024]

Example 2 Synthesis of γ-hexyl-γ-lactone 626 g (5.4 mol) of heptanol was charged into a 1-liter 4-diameter flask and heated until the temperature inside the flask reached 145°C. Next, 51.6 g (0.6 mol) of methyl acrylate, 69.6 g (0.6 mol) of heptanol, 0.5 g of trimethylbenzylammonium chloride and di-t
A solution of 4.4 g (0.03 mol) of -butyl peroxide is added dropwise to a flask in a reflux state (145° C. to 150° C.) over a period of 6 hours. After the dropwise addition is completed, the reaction is continued for an additional hour while refluxing (150°C). After the reaction was completed, unreacted heptanol was recovered from the cooled reaction product under reduced pressure to obtain 130 g of a residue. The obtained residue was distilled to obtain 87.7 g of γ-hexyl-γ-lactone with a purity of 99.5% (
A yield of 86.0%) was obtained.

[0025]

[Examples 3 to 16] According to the synthesis methods of Examples 1 and 2, alcohols of formula (2), 2-alkenoic acid esters of formula (3), organic peroxides, and nitrogen-containing compounds were prepared. Various γ-lactones of formula (1) were produced by appropriately combining them. The results (yield) are shown in Table 1.

[0026]

[Table 1]

[0027]

[Comparative Examples 1 to 5] Examples 1 and 2 were carried out except that conventionally known catalysts such as phosphates, sulfates, mineral acids, and organic acids were used instead of the nitrogen-containing compound of the present invention. According to the synthesis method of Example 1 and Example 2, various formulas (1)
γ-lactones were produced and the yields were compared. The results are shown in Table 2.

[0028]

[Table 2]

As can be seen from the tables of Examples and Comparative Examples above, the present invention in which the reaction is carried out in the presence of a nitrogen-containing compound has a higher yield than the conventional method in which the reaction is carried out in the presence of a conventionally known catalyst. A difference in advantage is recognized.

[0030]

Effects of the Invention According to the present invention, products accompanying side reactions can be suppressed, and the formula (
It becomes possible to provide a new manufacturing method capable of synthesizing γ-lactones in 1). That is, it provides an industrially advantageous manufacturing method in which the alcohol of formula (2) and the 2-alkenoic acid ester of formula (3) are reacted in just one step in the presence of an organic peroxide and a nitrogen-containing compound. It is.

Furthermore, the γ-lactones of formula (1) that can be provided by the present invention have fruit-like, peach-like, butter-like,
It has a milk-like aroma and is useful as a material for mixed fragrances for food and cosmetics.

Claims (1)

[Claims] Claim 1: The following formula (2) [Formula 1] In the formula, R1 represents a hydrogen atom and a C1 to C15 alkyl group, R2 represents a hydrogen atom, a methyl group, and an ethyl group, and R1 and R2 are the same. represents a butylene group and a pentylene group, and alcohols represented by the following formula (
3) [Formula 2] In the formula, R3 represents a hydrogen atom and a C1 to C15 alkyl group, R4 and R5 may be the same or different and represent a hydrogen atom and a methyl group, respectively, and R6 represents a C1 to C8 alkyl group. The following formula (1), which is characterized by heating and reacting 2-alkenoic acid esters having an alkyl group, in the presence of an organic peroxide and a nitrogen-containing compound:
embedded image A method for producing γ-lactones represented by the following formula, wherein R1, R2, R3, R4 and R5 have the above-mentioned meanings.