JPH0333695B2 - - Google Patents

Description

[Detailed description of the invention]

Glutaraldehyde is an important intermediate raw material for various chemical products, and is also a compound often used in applications such as leather tanning agents, microcapsule hardening agents, disinfectants, crosslinking agents, and enzyme immobilization agents. Glutaraldehyde is currently produced primarily by hydrolyzing 2-alkoxydihydropyran compounds produced in the Diels-Alder reaction of acrolein and vinyl ether. However, this method has the disadvantage that raw materials are expensive and generally difficult to obtain. In addition, a method of oxidizing 1,5-pentanediol is also known, but this method also has the disadvantages that the raw materials are expensive and the purity of the obtained glutaraldehyde is very poor. Therefore, glutaraldehyde is extremely expensive compared to other chemical products, and it is hoped that a method for producing glutaraldehyde of high purity using inexpensive raw materials that can be easily synthesized chemically will be developed. ing. From such an industrial standpoint, it is hoped that a method for producing glutaraldehyde using cyclopentene or a cyclopentene derivative, which can be obtained industrially at relatively low cost, as a raw material will be developed. The method for producing glutaraldehyde by oxidizing cyclopentene or cyclopentene derivatives generally involves synthesizing 1,2-cyclopentanediol from cyclopentene, and oxidizing this 1,2-cyclopentanediol with an oxidizing agent such as lead tetraacetate or periodic acid. A method of oxidizing is known. Although this method has good selectivity, it has the disadvantage that lead tetraacetate and periodic acid are stoichiometrically consumed as an oxidizing agent rather than as a catalyst. In addition, a method is known in which cyclopentene is reacted with ozone to form ozonide, which is then reductively decomposed to obtain glutaraldehyde. However, this method has the disadvantage that it is not suitable for production on an industrial scale because ozonide, which has a high risk of explosion, is produced as a reaction intermediate. Recently, a method has been proposed in which cyclopentene or cyclopentene oxide is catalytically oxidized with hydrogen peroxide in the presence of a molybdenum compound (for example, Japanese Patent Publication No. 51-28606;
No. 33526). However, this method also has some serious drawbacks. Firstly, the reaction must be carried out in a non-aqueous system since the reaction stops due to the presence of water. That is, commercially available low concentration aqueous hydrogen peroxide solutions cannot be used, and water-free hydrogen peroxide obtained by extraction with an organic solvent must be used. Even so, water will still be produced when hydrogen peroxide reacts with cyclopentene or cyclopentene oxide.
This water must be removed continuously. The second problem is that a large amount of 1,2-cyclopentenediol is produced as a by-product. This diol is a substance that is very difficult to separate from glutaraldehyde and must be suppressed as a by-product as much as possible since it reduces the purity of the glutaraldehyde product. The third and most serious problem is that the generated glutaraldehyde reacts further.
Glutaraldehyde is a very unstable substance, and if the reaction is continued without being separated from the reaction system even after it has been produced, the produced glutaraldehyde may be further oxidized and become a carboxylic acid, or it may become a carboxylic acid due to a condensation reaction. It will end up being wasted. For the reasons mentioned above, it is clear that it is difficult to produce highly pure glutaraldehyde using this method, and it is also difficult to improve the yield. Therefore, it is considered to be very difficult to industrialize the method for producing glutaraldehyde by oxidizing cyclopentene using hydrogen peroxide. In general, when manufacturing various chemical products, it goes without saying that it is easy to carry out and that the reaction rate is high, but when manufacturing glutaraldehyde, it is necessary to take into account its instability. There must be. Therefore, even if the reaction rate is simply high, a manufacturing method in which the produced glutaraldehyde undergoes further reaction or energy or materials are wasted in removing impurities is not considered to be an industrially appropriate method. The present inventors have conducted extensive research to achieve the above-mentioned object, and have proposed a method for producing glutaraldehyde using a cyclopentyl peroxide compound as a raw material (Japanese Patent Application No. 57-3867 (Japanese Patent Publication No. No. 38773), No. 57-159276 (Special Publication No. 2-
No. 7299). The present inventors have conducted further research to facilitate the stabilization and purification of glutaraldehyde precursors, and as a result, have discovered the following new method.
The present invention has now been completed. That is, the present invention
selected from the group consisting of copper, silver, boron, aluminum, tin, lead, titanium, zirconium, vanadium, chromium, molybdenum, tungsten, manganese, iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium and platinum In the presence of a catalyst containing at least one element and/or its compound, with the general formula R ₁ OH (R ₁ is a linear or branched aliphatic or alicyclic organic group having 1 to 12 carbon atoms). A monohydric alcohol represented by the formula HO−Z ₁ −OH (Z ₁ is a linear or branched aliphatic or alicyclic organic group having 2 to 12 carbon atoms. On the carbon of _{Z 1} Furthermore, 1 to 4 hydroxyl groups may be bonded.However, those in which two or more hydroxyl groups are bonded to the same carbon are excluded) At least one kind selected from the group of polyhydric alcohols shown in alcohol and general formula (R ₂ is hydrogen or a linear or branched aliphatic, alicyclic or aromatic organic group having 1 to 9 carbon atoms) or the general formula (R ₃ and R ₄ are each hydrogen or an organic group having 1 to 10 carbon atoms. R ₃ and R ₄ may be connected to form a ring.) General formula X-(CH ₂ ) ₃ -Y (X and Y are each

【formula】

[Formula] or formyl group. _R5 and _R6 are each _R1 or HO- _Z1 . However, X and Y may be the same, but the case where both are formyl groups is excluded) and the general formula (R ₇ and R ₈ are each R ₁ or HO-Z ₁ ). The present inventors have so far developed a cyclopentyl peroxide compound, that is, as a bone core.

We have been conducting research on the synthesis of aldehydes by decomposing compounds with the structure [Formula].

It has been newly discovered that an acetal compound can be obtained by reacting a compound having the structure [formula] with an alcohol as claimed in the claims of this patent in the presence of a metal catalyst as claimed in the claims. That is, the general formula (Here a, b, c and n are real numbers,
4a + 2b + 2c = n, n4), but this reaction was completely unknown and is a new reaction. It has been found that when the method of the present invention is used in a method for producing glutaraldehyde, the operation is safe and it becomes possible to produce highly pure glutaraldehyde. That is, the cyclopentyl peroxide compound described in the claims, which is industrially synthesized from cyclopentene or cyclopentene oxide, is catalytically decomposed in a theoretical amount or more of alcohol to convert the unstable peroxide compound into stable acetals. By converting to , the risk of runaway reaction or explosion can be completely eliminated. In addition, with hydroxycyclopentyl oxide compounds, it was impossible to separate the by-product cyclopentanediol and oligomers, but the acetals obtained in the present invention are thermally stable and can be easily purified by distillation. High purity glutaraldehyde precursor can be obtained. Furthermore, these acetals are acids,
It also has the advantage that it is chemically stable and can be stored for a long time if care is taken to prevent moisture from entering. The acetals thus obtained are hydrolyzed using a known method, and by distilling off the by-product alcohol, a highly pure aqueous glutaraldehyde solution can be obtained. The acetals produced by the method of the present invention have the general formula X-(CH ₂ ) ₃ -Y (X and Y are each

【formula】

[Formula] or formyl group. R ₅ and R ₆ are each R ₁ or HOZ ₁ . However, X
and Y may be the same, but excluding the case where both are formyl groups) and general formula (R ₇ and R ₈ are each R ₁ or HOZ ₁ ). Specific examples of these acetals are: etc. Depending on the reaction conditions, various acetals as described above may be produced simultaneously. However, all acetals can be easily separated by rectification, and can all be converted into glutaraldehyde by hydrolysis. The catalyst used in the process of the invention is copper,
silver, boron, aluminum, tin, lead, titanium,
It is at least one or a mixture of a single substance or a compound of zirconium, vanadium, chromium, molybdenum, tungsten, manganese, iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium, and platinum. These compounds are used in the form of complexes of elements with zero valence, or inorganic or organic compounds with various valences. Compounds of these elements include oxides, mixed oxides, hydroxides, oxyacids, heteropolyacids, salts and esters thereof. These include those derived from inorganic hydroacids, oxyacids, and organic carboxylic acids or sulfonic acids having 40 or less carbon atoms. Complexes of these elements are mainly called organometallic complexes, which are coordinated by organic groups and/or inorganic groups. Examples of catalysts that can be used in the present invention are as follows. Namely, simple metals such as copper, silver, aluminum, tin, lead, titanium, vanadium, chromium, molybdenum, tungsten, manganese, iron, cobalt, nickel, rhodium, palladium, and platinum; copper-nickel, copper-platinum, copper- Palladium, copper-gold, silver-platinum, silver-palladium, gold-
Alloys such as platinum, cobalt-iridium, cobalt-palladium, cobalt-rhodium, cobalt-iron, nickel-palladium, nickel-iron;
Oxides of copper, silver, boron, aluminum, tin, lead, titanium, vanadium, chromium, molybdenum, tungsten, manganese, iron, cobalt, nickel, rhodium, palladium, osmium, iridium and platinum (Cu ₂ O, CuO, Ag _2O , AgO,
FeO, Fe ₂ O ₃ , Fe ₃ O ₄ , CoO, Co ₃ O ₄ , NiO,
_RuO2 , PdO, _OsO4 , _IrO2 , _PtO2 , _MnO2 ,
_{CrO2 , Cr2O3} , _CrO3 , _MoO2 , _Mo2O5 , _{MoO3 ,
WO2 , W2O5} , _WO6 , _VO2 , _V2O5 , _{ZrO2 ,}
TiO ₂ , B ₂ O ₃ , Al ₂ O ₃ , PbO, etc.); oxychlorides, fluorides, chlorides, bromides, iodides of these elements; inorganic acids such as nitrates, sulfates, phosphates of these elements salt, pyrophosphate, polyphosphate, borate, carbonate, formate, acetate, propionate, butyrate, isobutyrate, caproate, caprylate, laurate, naphthenate, Organic acid salts such as stearates, oxalates, succinates, glutarates, adipates, benbrozoates, phthalates, benzenesulfonates; acetylacetonates and phthalocyanine complexes of these elements;
The metal carbonyls of these elements (V(CO) ₆ , Cr
(CO) ₆ , Mo(CO) ₆ , W(CO) ₆ , Fe(CO) ₅ , Ni
(CO) ₄ , Ru ₃ (CO) ₁₂ , Os ₃ (CO) _12, etc.); oxyacids such as molybdic acid, chromic acid, osmic acid, tungstic acid and corresponding heteropolyacids, and alkali metal salts of the above acids. Alternatively, alkaline earth metal salts may be mentioned. There is no problem in using a mixture of one or more of the above-mentioned single substances and compounds. Furthermore, according to known methods, alumina, silica,
It is also possible to use carriers supported on silica alumina, zeolite, etc., or in some cases, organic polymers. In the present invention, a cyclopentyl peroxide compound represented by the following general formula is used. Here, R ₂ is hydrogen or an organic group having 1 to 9 carbon atoms. Typical organic groups include alkyl groups, cycloalkyl groups, aryl groups, acyl groups, etc. Organic groups containing halogen, hydroxyl groups, formyl groups, hydroperoxy groups, peroxyalkyl groups, etc. are also used. can. This cyclopentyl peroxide compound can be synthesized in high yield by reacting cyclopentene oxide with hydrogen peroxide or an organic hydroperoxide in the presence of an acid such as sulfuric acid, hydrochloric acid, or a cation exchange resin. Also, this cyclopentyl peroxide compound has the general formula (X is OSO ₃ R′, OSO ₂ H, OSO ₂ R′, OCOR′,
Cl, Br, I, ClO ₄ , OH or OR'. However, as shown in (R' is an alkyl group, cycloalkyl group, or aryl group having 1 to 16 carbon atoms), it can also be synthesized by reacting a β-hydroxycyclopentane derivative with hydrogen peroxide or an organic hydroperoxide. be able to. In the present invention, a cyclopentyl peroxide compound represented by the following general formula can also be used. Here, R ₃ and R ₄ are each hydrogen or an organic group having 1 to 10 carbon atoms. Typical examples of this organic group are an alkyl group, a cycloalkyl group, and the like, which are organic groups having a halogen, a hydroxy group, a formyl group, a hydroperoxy group, a peroxyalkyl group, a cyclic peroxyketal, and the like.
R ₃ and R ₄ may be connected to form a ring. This cyclopentyl peroxide compound can be synthesized by reacting cyclopentene oxide with ketone peroxide in the presence of an acid such as sulfuric acid, hydrochloric acid, or a cation exchange resin. This cyclopentyl peroxide compound can also be synthesized by reacting a ketone or aldehyde with β-hydroxycyclopentyl hydroperoxide, which can be synthesized by the method described above, in the presence of an acid such as sulfuric acid, hydrochloric acid, or a cation exchange resin. be able to. Specific examples of these cyclopentyl oxide compounds are:

【formula】 【formula】

【formula】

【formula】

【formula】

【formula】 【formula】

It is a compound such as. In this reaction, there is no problem even if one or more of the above cyclopentyl peroxide compounds are reacted as a mixture. The alcohol used in the method of the present invention is a monohydric alcohol having the general formula R ₁ OH (R ₁ is a linear or branched aliphatic or alicyclic organic group having 1 to 12 carbon atoms), or a monohydric alcohol having the general formula HO-Z ₁ -OH (Z ₁ is a linear or branched aliphatic or alicyclic organic group having 2 to 12 carbon atoms. 1 to 4 hydroxyl groups are further bonded to the carbon of _{Z 1} . (However, those in which two or more hydroxyl groups are bonded to the same carbon are excluded.) At least one alcohol selected from the group of polyhydric alcohols shown in Specific examples of these alcohols include:
Methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, n-amyl alcohol, isoamyl alcohol, n-hexano-
octanol, dodecanol, cyclopentanol, cyclohexanol, cyclododecanol, ethylene glycol, propylene glycol, 1,5-pentanediol, 1,2-hexanediol, glycerin, 1,2-cyclopentanediol, 1,2 -cyclohexanediol,
Examples include 1,3-cyclododecanol. When carrying out the present invention, the above-mentioned cyclopentyl peroxide compound may be dissolved only in the above-mentioned alcohol without using any other solvent, and the reaction may be carried out in contact with the catalyst, or other solvents may be used in addition to the above-mentioned alcohol. The reaction may be performed after dilution. Any solvent that does not react with the raw material alcohol, cyclopentyl peroxide compound, and produced acetals can be used for this purpose. Examples of such solvents include hydrocarbons having 5 to 12 carbon atoms, carboxylic esters containing organic groups having 1 to 12 carbon atoms, phosphoric esters, sulfonic esters, carboxylic acid amides, and ethers. Specific examples of these solvents include n-pentane, isopentane, cyclopentane, cyclopentene, n-hexane, isohexane, cyclohexane, octane, dodecane, benzene, toluene, xylene, ethylbenzene, ethyl acetate,
Butyl acetate, isoamyl acetate, cyclohexyl acetate, butyl propionate, ethyl benzoate, dimethyl phthalate, diethyl phthalate, dimethylformamide, dimethylacetamide, triethyl phosphate, trihexyl phosphate, trioctyl phosphate, dimethyl methanephosphonate, diethyl ether, anisole and so on. When carrying out the method of the present invention, the concentration of cyclopentyl peroxide compound in the reaction solution is 0.1-50w to prevent heat generation and runaway risk due to rapid reaction.
%, preferably 0.5-20wt%. The amount of alcohol to be used may be determined within a range that satisfies such concentration conditions, but the amount of alcohol to be used is preferably 4 moles or more per 1 mole of the cyclopentyl peroxide compound. Further, the maximum amount to be used may be any value that falls within the above-mentioned concentration range of the cyclopentyl peroxide compound. The amount of catalyst used in acetalizing cyclopentyl peroxide compounds according to the method of the present invention can vary over a wide range depending on its activity, but ranges from 10 -6 mol to 10 ^-6 mol per mol of cyclopentyl peroxide compound. ^-1 mole,
In particular, it is preferred to use an amount of 10 ^-5 mol to 10 ^-1 mol. The temperature at which the method of the present invention is carried out is undesirably high, at which the cyclopentyl peroxide compound thermally decomposes non-catalytically and produces by-products other than acetals, and too low a temperature is economically unfavorable due to the slow reaction rate. Therefore, this method uses 0℃
The temperature range is preferably up to 200°C, and it is particularly desirable to carry out the reaction at a temperature below the boiling point of the alcohol used in the reaction. This reaction can be carried out either batchwise or continuously, and although the reaction time varies depending on the reaction temperature and the composition of the reaction system, it is usually sufficient to carry out the reaction for 10 hours. Example 1 β-hydroxycyclopentyl hydroperoxide as a raw material was prepared by the following method. Amberlyst in a 300 c.c. capacity three-necked flask equipped with a stirrer, reflux condenser and dropping funnel.
After adding 8 g of 15 (manufactured by Rohm & Haas, strong acidic cation exchange resin) and 50 g of dimethyl phthalate, 40 g of cyclopentene oxide and 18 wt% of hydrogen peroxide were added from the dropping funnel while stirring while keeping the flask at 30°C. dimethyl phthalate solution
110 g of the mixture was added dropwise over 1 hour. After the dropwise addition was completed, the reaction was continued for an additional 3 hours at 30°C, and then the catalyst was separated. The solution was subjected to preparative liquid chromatography using silica gel as the stationary phase and benzene ethanol = 20:1 as the mobile phase to obtain β-hydroxycyclopentyl hydroperoxide.
Got 40g. The reaction between the obtained β-hydroxycyclopentyl hydroperoxide and ethanol was carried out as follows. Pd/C (Pd5%
Support) 7.0g of powder and 45g of ethanol were heated, and while the ethanol was boiling, the above β-
Hydroxycyclopentyl hydroperoxide
A solution prepared by diluting 21.0 g with 70 g of ethanol was added dropwise over 1 hour. After the dropwise addition was completed, the reaction was continued at boiling temperature for another 6 hours. FFAP (free fatty acid polyester)
Analysis by gas chromatography using a column with a liquid phase of cis- and trans-
2,6-diethoxytetrahydropyran 10.6g,
6.7 g of 5,5-diethoxypentanal and 1,
It was found that 15.1 g of 1,5,5-tetraethoxypentane was produced. The yield of acetals was 90%. It was confirmed by iodometry that no unreacted peroxide remained in the reaction solution. Example 2 The raw material cyclopentyl peroxide compound, 4-ethyl-4-methyl-2,3,5-trioxabicyclo[4,3,0]nonane, was synthesized from cyclopentene oxide and methyl ethyl ketone peroxide in the same manner as in Example 1. However, the reaction temperature was 40℃, and cyclopentene oxide
40g, 60g of methyl ethyl ketone peroxide 48g
A solution diluted with dimethyl phthalate was used.
After the completion of the dropwise addition, the reaction was carried out at 40°C for 3 hours, and 4-ethyl-4-methyl-2,3,5-trioxabicyclo[4,3 ,0]40g of nonane was obtained. Acetalization of this compound was carried out in exactly the same manner as in Example 1. However, Pd/Al ₂ O ₃ as a catalyst
(Amount of Pd supported: 1%) 16.0 g of powder was used, 34.4 g of cyclopentyl peroxy compound was used, and 50 g of ethanol was used in the flask and 70 g in the dropping funnel. After the reaction was completed, gas chromatography analysis revealed 12.8 g of cis- and trans-2,5-diethoxytetrahydropyran, 6.0 g of 5,5-diethoxypentanal, and 1,1,5,5-
17.8g of tetraethoxypentane was produced.
The yield of these acetals was 90%. Example 3 A raw material β-hydroxycyclopentyl t-butyl peroxide was prepared by the following method by reacting cyclopentene oxide with t-butyl hydroperoxide. After stirring, a reflux condenser and a dropping funnel were added.
Amberlyst 15 in a three-necked flask with a capacity of 500c.c.
After adding 7g of and 100g of t-butanol,
The temperature was raised to .degree. C., and a solution consisting of 44 g of cyclopentene oxide, 52 g of t-butyl hydroperoxide, and 100 g of t-butanol was added from the dropping funnel over 2 hours while stirring. After reacting at 40° C. for 5 hours, the reaction solution was distilled under reduced pressure to obtain 40 g of β-hydroxycyclopentyl t-butyl peroxide. β-Hydroxycyclopentyl t-butyl peroxide was reacted in ethanol in the same manner as in Example 1 using palladium black as a catalyst. That is, 0.89 g of palladium black was placed in the same flask as in Example 1.
Add 60 g of ethanol and add β-hydroxycyclopentyl t-butyl peroxide from the dropping funnel.
A solution prepared by dissolving 39.5 g in 60 g of ethanol was added dropwise over 0.5 hours at the boiling temperature of ethanol. After completion of the dropwise addition, heating and stirring were continued for 8 hours. After distilling off excess ethanol from the reaction solution, fractional distillation was performed using a rotating band type rectification distillation column, resulting in cis-2,
5-diethoxytetrahydropyran at 51℃/3mm
9.8g at the boiling point of Hg, 2.9g at trans-2,5-diethoxytetrahydropyran (65℃/2mmHg), 5,
5-diethoxypentanal (81℃/2mmHg)
9.1 g of 1,1,5,5-tetraethoxypentane (99°C/2 mmHg) were obtained. The yield of acetals was 89%. Example 4 Cyclopentene oxide and hydrogen peroxide were reacted using Amberlyst 15 as a catalyst in exactly the same manner as in Example 1, and after the reaction was completed, the catalyst was separated and β
-Hydroxycyclopentyl hydroperoxide
A 23wt% dimethyl phthalate solution was obtained. Using this reaction solution without separating β-hydroxycyclopentyl hydroperoxide, a reaction with methanol was carried out as follows. Equipped with stirrer, reflux condenser and dropping funnel
0.90 g of platinum black and 120 g of methanol were placed in a 500 c.c. three-necked flask and heated, and 100 g of the above reaction solution was added from the dropping funnel over 1 hour while the methanol was boiling. After the addition was completed, the mixture was further heated and stirred for 8 hours, and then analyzed by gas chromatography.
Dimethoxytetrahydropyran 10.2g, 5,5-
Dimethoxypentanal 5.1g and 1,1,5,
It was found that 11.5 g of 5-tetramethoxypentane was produced. The yield of these acetals is
It was 85%. Example 5 The reaction between β-hydroxycyclopentyl hydroperoxide obtained in the same manner as in Example 1 and ethylene glycol was carried out as follows. TiO in a 300 c.c. capacity three-necked flask equipped with a stirrer, reflux condenser, and dropping funnel.
1.12 g of (C ₅ H ₇ O ₂ ) ₂ and 50 g of ethylene glycol were added and heated to 90° C., and a solution consisting of 30 g of β-hydroxycyclopentyl hydroperoxide and 90 g of ethylene glycol was added dropwise from the dropping funnel over 1 hour. After the dropwise addition was completed, the reaction was further continued at 90°C for 4.5 hours. After the reaction was completed, the acetal was separated using preparative liquid chromatography, and 5.6 g of 4-(2',5'-dioxacyclopentyl)butyl-1-al and 1,3-bis(2',5'- 23.7 g of dioxacyclopentyl)propane were obtained. The yield of these acetals was 65%. Examples 6-26 Various cyclopentyl peroxide compounds were prepared in the same manner as in Examples 1 to 3, and acetalized in the presence of various catalysts. The results are shown in Table 1.

【table】

【table】

【table】

【table】

【table】

【table】 /
／ ＼
R ₁ O
R ₁ O OR ₁
B
C

A
(R ₁ represents the organic group of the raw alcohol.)
2) Solvents used other than raw material alcohol.
3) Includes the addition time of the cyclopentyl compound.

Claims (1)

[Claims] 1 Copper, silver, boron, aluminum, tin, lead, titanium, zirconium, vanadium, chromium,
In the presence of a catalyst containing at least one element and/or compound thereof selected from the group consisting of molybdenum, tungsten, manganese, iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium and platinum, the general formula R ₁ OH (R ₁ is a linear or branched aliphatic or alicyclic organic group having 1 to 12 carbon atoms), or a monohydric alcohol with the general formula HO−Z ₁ −OH (Z ₁ is It is a linear or branched aliphatic or alicyclic organic group having 2 to 12 carbon atoms.1 to 4 hydroxyl groups may be further bonded to the carbon of _Z1.However , if the hydroxyl groups are the same At least one alcohol selected from the group of polyhydric alcohols represented by (excluding those with two or more bonds on carbon), and (R ₂ is hydrogen or a linear or branched aliphatic, alicyclic or aromatic organic group having 1 to 9 carbon atoms) or the general formula (R ₃ and R ₄ are each hydrogen or an organic group having 1 to 10 carbon atoms. R ₃ and R ₄ may be connected to form a ring.) It is characterized by _{General formula : _ _ _} may be the same as Y, but excluding the case where both are formyl groups) and general formula ( _R7 and _R8 are each _R1 or HO- _Z1 ) A method for producing a glutaraldehyde acetal.