JPS5843376B2 - Fuhouwa aldehyde no seizouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the production of α,β-unsaturated aldehydes.

More specifically, it relates to the production of α,β-unsaturated aldehydes by subjecting acetals of specific aldehydes to thermal rearrangement.

The unsaturated aldehyde that is the object of the present invention has traditionally been a useful compound in the terpene chemical industry, particularly in perfumery, pharmaceuticals,
It is an industrially valuable compound as a pesticide or an intermediate thereof.

Conventionally, as a method for producing such unsaturated aldehydes, for example, a carbonyl compound and acetylene are reacted to produce acetylene alcohols, and this is further rearranged (He1v, Chim, Acta 421946 (1)
959)) or a method of dehydrohalogenating α-halogenoacecules in the presence of an alkali (Can,
J, Ch, e m.

49 2321 (1971)) by oxidation of the corresponding allyl alcohol (PJ, 0.R, □699 (196
6)) etc. are known.

However, such conventional methods have industrial disadvantages due to the length and complexity of the reaction steps and the high cost of reaction reagents.

Another method for producing higher α, β unsaturated aldehydes is a method in which lower α, β unsaturated aldehydes and allyl alcohols are heated under dehydration conditions (Japanese Patent Laid-Open No. 48-61
No. 413), a method by reaction of butadiene-1-alkyl ether with allyl alcohols (Swiss Patent No. 47)
3753), but since the unsaturated aldehyde produced in this way uses allyl alcohols, the carbon-carbon double bond is not only at the 2,3 (α, β) position but also at the 6.7 position. It also exists in

Therefore, if an aldehyde having double bonds only at the 2- and 3-positions is required, a process such as washing with water is required, and for α- and β-unsaturated aldehydes having double bonds other than the 6- and 7-positions, further Requires a complicated process.

As a result of repeated research into a method that does not have the above-mentioned drawbacks, the inventors of the present invention have found that α,β-unsaturated aldehydes can be easily produced by thermal rearrangement of relatively low unsaturated aldehydes and acetals of saturated alcohols. This is what we have discovered and arrived at the present invention.

The present invention has been achieved based on such knowledge, and is based on the following general formula [I] [wherein R1s R2s R3s R4 are the same or different and represent a hydrogen atom or a hydrocarbon residue having 1 to 20 carbon atoms] .

R9, Rlo, R1□, R13, and R14 are the same or different and represent a hydrogen atom or a saturated hydrocarbon residue having 1 to 40 carbon atoms.

] The following general formula (4) is characterized by subjecting an acetal represented by the above formula to thermal rearrangement [In the formula, R1 to R4 are the same as defined above, and R represents R5 or R6.

] This is a method for producing an α,β-unsaturated aldehyde represented by:

The method of the present invention will be explained in detail below.

[Starting material]

In the acecool represented by the general formula [I] which is the starting material in the method of the present invention, R1-R4 are the same or different hydrogen atoms or saturated or unsaturated hydrocarbon residues having 1 to 20 carbon atoms, and R3 is is especially carbon number 1
~20 saturated or unsaturated hydrocarbons are preferred.

Further, R, , R6 are the same or different.

Here, R9, Rlo, R11, R12, R13 and R14 are the same or different, and each represents a hydrogen atom or a saturated hydrocarbon residue having 1 to 40 carbon atoms, and there is no reaction-inert substitution in the hydrocarbon residue. It may have a group.

Examples of the substituent include saturated aliphatic hydrocarbons and alicyclic hydrocarbons.

One of the preferred specific compounds of the above formula ○ in the present invention
An example will be explained below.

These are merely examples, and it goes without saying that the present invention is not limited thereto.

When the group in the formula (1) is -X, the following are preferable examples of W- and -X, respectively.

(A) W- group and R5s in the -X group Other examples of R6 include methyl, ethyl, n-propyl, n-pentyl, n-hexyl-1n-hebutyl-1n-octyl1n-nonyl-
Straight chain or branched saturated alkyl groups such as 1n-decanoyl, isopropyl, isobutyl, and inoctyl; for example, hydrocarbons having an alicyclic group in the side chain such as 2-cyclohexylethyl.

A specific compound may be one in which a W- group and a -X group are appropriately combined.

The most industrially useful compounds are, for example, those listed below.

(a) A phytylaldehyde represented by the combination of (W-1) and (X-t) is obtained.

This is a precursor of phytol, and it can be easily converted into phytol by selective hydrogenation.

The rearrangement reaction of the present invention can be carried out either in the presence or absence of a catalyst.

When an acid catalyst is used as a catalyst, unsaturated aldehydes can sometimes be obtained in good yields.

The acid catalyst used in this case may be any catalyst as long as it exhibits acidity, and includes various catalysts such as inorganic acids, organic acids, solid acids, and strong acid salts of weakly basic substances.

The amount of catalyst varies depending on the PKa value of the catalyst, but is generally 0.00001 mole to 10 moles, preferably 0.001 mole to 5 moles, based on the compound [I].

Specific examples of acid catalysts include inorganic acids such as hydrochloric acid,
Sulfuric acid, perchlorate, phosphoric acid, boric titanate, hypophosphorous acid, metaboric acid, etc.; examples of organic acids include formic acid, acetic acid,
Propionic acid, butyric acid, monochloroacetic acid, dichloroacetic acid,
Aliphatic carboxylic acids such as trichloroacetic acid, stearic acid, valmitic acid, acrylic acid, oxalic acid, tartaric acid, maleic acid, etc., alicyclic carboxylic acids such as hexahydrobenzoic acid, naphthenic acid, etc., benzoic acid, o-lm- or P-toluic acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid 1. Aromatic carboxylic acids such as α- or β-naphthoic acid, anisic acid, chlorobenzoic acid, cyanobenzoic acid, brobenzoic acid, etc., such as methanesulfonic acid, ethanesulfonic acid, cyclohexanesulfonic acid, benzenesulfonic acid, p-toluene Aliphatic-1-cycloaliphatic- or aromatic-sulfonic acids such as sulfonic acids; phosphines such as methylphosphinic acid, ethylphosphinic acid, phenylphosphinic acid, methylphosphinic acid, ethylphosphinic acid, penzylphosphinic acid, etc. Acid or phosphonic acid; Examples of solid acids include oxide-based solid acids such as silica gel, silica alumina, alumina, titanium oxide, germanium oxide, boron oxide, etc., as well as salts such as NH4Cl-supported silica alumina and zinc chloride-supported silica alumina. or acid-supported solid acids; examples of strong acid salts of weak basic substances include ammonium chloride, ammonium nitrate, ammonium nitrate, ammonium phosphate, ferric chloride, zinc chloride, aluminum chloride,
Examples include calcium chloride, tin chloride, ammonium P-toluenesulfonate, and tetraethylammonium P-toluenate.

The various acid catalysts described above are merely exemplified, and the present invention is not limited thereto in any way.

The acid catalyst used in the present invention is characterized by its acid strength (PK
Preference is given to those in which a) is in the range 0 to 10, preferably in the range 0 to 7, particularly preferably in the range 0 to 5.

Although this reaction can be carried out in either a gas phase or a liquid phase, it is generally preferable to carry out the reaction in a liquid phase, in which case a solvent may or may not be used.

When using a solvent, any solvent may be used as long as it does not adversely affect the reaction, and for example, the following solvents can be used.

(1) Aliphatic hydrocarbons; e.g. n-hebutane, n-decane, n-toticane, etc. (11) Aromatic hydrocarbons; e.g. benzene, toluene, etc.
, m, p-xylene, etc. Ethylbenzene, trinotylbenzene Tetramethyl benzene Schiff)
) enyl, terphenyl, etc. (iii) Alicyclic hydrocarbon; for example, cyclohexane,
Methylcyclohexane, decalin, etc. (v; Halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzene, bromobenzene, etc. (v) Ethers; such as di-n-amyl ether diisoamyl ether benzyl ether) Methyl cellosolve, diethylene ether (v) Esters such as methyl benzoate, ethyl benzoate, diethyl phthalate, dibutyl phthalate, dioctyl phthalate, ethyl acetate, butyl acetate, etc. (v+D ketones; such as benzophenone, acetophenone, etc.) The reaction of the present invention, which includes
It is appropriate to conduct the reaction at a temperature in the range of 0 to 450°C, and the pressure may be reduced, normal pressure, or increased pressure.

The reaction time varies depending on the reaction temperature, gas phase, liquid phase, etc., but is generally several seconds or more.

In particular, in the case of a liquid phase, it is preferably 10 seconds to 10 hours, particularly 30 seconds to 5 hours.

The method of the present invention can also be carried out in a batchwise or continuous manner.

Next, the present invention will be described in detail with reference to Examples, but the present invention is not limited thereto.

In addition, the parts in the middle part of the examples are by weight unless otherwise specified.

Example 1 25 parts of 3-methyl-2-butynal 250 parts of benzene (
Capacity) 100 parts of isoamyl alcohol (NH4) 280
Transfer 41.65 parts to a distillation column (designed to have a column packed with molecular sieves 3A for dehydration at the top of the column so that the benzene distilled out can be returned to the distillation column while dehydrating it) using a nitrogen injection tube thermometer. The insoluble (N)(4)2SO4 in the product was removed by decantation, and 35 parts of Na2CO was added and fractionated under vacuum to obtain B, P98. °C/0.3 mmHg 30
I got the department.

As a result of IR, NMR, and mass spectrum analysis, this fraction is 3
-Methyl-2-butinal-diisoamyl acecool was confirmed.

Examples 2 to 16 When 3-methyl-2-butynal diisoamyl acecool synthesized in Example 1 was charged into a sealed tube and reacted under the conditions shown in Tables 1 and 2, 6,7-dihydrocitral (3, 7-
dimethyl-2-octenal) was obtained.

The results are shown in Tables 1 and 2. The molecular weight of 6,7-cyhydrocitral was 154 as a result of mass vector analysis, which matched the IR and NMR spectra of standard 6,7-cyhydrocitral.

In the table, AC-1 represents 3-methyl-2-butynal diisoamyl acecure, and DCT represents 6,7-cyhydrocitral.

Example 22 3-Methyl 2-butinal diethylacecur 10 parts 3
-7.11-Trimethyl-dodecanol 30 parts NH4N
030.1 part was charged and stirred in the same manner as in the example, ethanol was distilled off at room temperature, and the product was transferred to a distillation flask containing 31 parts of Na2C0 and distilled. B, P2
20 parts of Hg was obtained at 35-255°C for 10.3 hours.

As a result of IR, NMR, and mass spectrometry analysis, this fraction was confirmed to be 3-methyl-2-butenal di(3,7-11-trimethyldodecanyl) acetal.

Example 18.19 3-Methyl-2-butenaludi(3,7,11-trimethyldodecanyl) acetal synthesized in Example 17 was charged into a sealed tube in the proportions shown in Table 3 and reacted under the conditions shown in Table 3. As a result, phytylaldehyde (3,7,11,15
-tetramethyl 2-hexaacenal) was obtained.

The results were as shown in Table 3.

In the table, AC-2 is 3-methyl-2-butenaruge (3,
7,11-trimethyldodecanyl) acetal as PHA
indicates phytylaldehyde.

Claims (1)

[Scope of Claims] 1 The following general formula CI) [In the formula, Ri p R2y R3 and R4 are the same or different and represent a hydrogen atom or a hydrocarbon residue having 1 to 20 carbon atoms, and Ro, Rlo, R, 1, R, 2, R13, and R1 are the same or different and represent a hydrogen atom or a saturated hydrocarbon residue having 1 to 40 carbon atoms. ] The acetal represented by the following general formula [phantom] [wherein R1 to R4 are the same as the above definitions, R is R6 or R6]
shows. ] The production of α,β-unsaturated aldehydes represented by