JP2846478B2 - Method for producing unsaturated alcohol - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an unsaturated alcohol, and preferably, it is possible to efficiently reduce an aldehyde group of an α, β-unsaturated aldehyde to thereby efficiently produce an unsaturated alcohol. The present invention relates to a method for producing alcohol.

Description of Related Art As a method for producing an unsaturated alcohol, a method for selectively reducing an aldehyde group of an α, β-unsaturated aldehyde is known. In particular, formula (I) 2,2,3-trimethyl-3-cyclopentene represented by
The unsaturated alcohol having a 1-yl group is known as a fragrance having both a fragrance like jade and a fragrance like sandalwood, and 2,2,3-trimethyl-3- represented by the above formula (I).
It is produced by selectively reducing only an aldehyde group from an α, β-unsaturated aldehyde having a cyclopenten-1-yl group.

For example, JP-B 56-36176 has the formula (II ′) 2-methyl-4- (2,2,3-trimethyl-3 represented by
-Cyclopenten-1-yl) -2-buten-1-al in the presence of isopropyl alcohol by selectively reducing only the aldehyde group using an aluminum alcoholate or a metal hydride compound to obtain a compound of the formula (III ′) 2-methyl-4- (2,2,3-trimethyl-3 represented by
A method for producing -cyclopenten-1-yl) -2-buten-1-ol is disclosed. ◇ However, in this method, the aluminum alcoholate or the metal hydride compound is 40 mol% based on the starting aldehyde.
In addition, isopropyl alcohol is also used in a large excess of 20 mole times or more of the raw material aldehyde,
Low productivity and not an efficient method.

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a method for efficiently producing an unsaturated alcohol from an α, β-unsaturated aldehyde.

The present inventors have conducted intensive studies to solve the above problems,
The present invention has been completed.

That is, the present invention produces an unsaturated alcohol from an α, β-unsaturated aldehyde by selectively reducing the aldehyde group using an aluminum alcoholate in the presence of a primary or secondary alcohol having 2 to 8 carbon atoms. In this case, the present invention provides a method for producing an unsaturated alcohol, wherein a reaction is carried out by adding a protonic acid.

In other words, an unsaturated alcohol is produced by selectively reducing an α, β-unsaturated aldehyde with respect to an aldehyde group in the presence of a primary or secondary alcohol having 2 to 8 carbon atoms, aluminum alcoholate and a protonic acid. It provides a method.

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, embodiments of the present invention will be described in detail.

Preferably, 0.7 to α, β-unsaturated aldehyde.
A primary or secondary alcohol having 2 to 8 carbon atoms in an amount of up to 15 mole times,
In the presence of 0.5 to 35 mol% of aluminum alcoholate based on α, β-unsaturated aldehyde and 0.005 to 30 mol% of protic acid based on α, β-unsaturated aldehyde,
This is a method for producing an unsaturated alcohol by selectively reducing an α, β-unsaturated aldehyde with respect to an aldehyde group.

The α, β-unsaturated aldehyde used in the present invention is not particularly limited as long as it has an unsaturated bond at the α, β-position of the aldehyde group, but is typically represented by the above formula (I). Compounds having a 2,2,3-trimethyl-3-cyclopenten-1-yl group.

In particular, the process of the present invention comprises reacting an α, β-unsaturated aldehyde of the formula (II) (II) (In the formula, R represents an alkyl group having 1 to 3 carbon atoms.) 2-alkyl-4- (2,2,3-trimethyl-
Using 3-cyclopenten-1-yl) -2-buten-1-al, a compound of the formula (III) (Wherein, R represents the above-mentioned meaning.) 2-alkyl-4- (2,2,3-trimethyl-
It can be preferably applied to a reaction for obtaining 3-cyclopenten-1-yl) -2-buten-1-ol and the like.

In the above formulas (II) and (III), R is a methyl group,
1 to 1 carbon atoms such as ethyl group, propyl group and isopropyl group
3 represents an alkyl group, preferably a methyl group or an ethyl group, particularly preferably a methyl group.

Although the unsaturated alcohol represented by the formula (III) is used as a fragrance, the one produced by this reaction has a slightly clear scent.

Primary or secondary having 2 to 8 carbon atoms used in the present invention
Examples of the lower alcohol include aliphatic alcohols, particularly ethyl alcohol, n-propyl alcohol, isopropyl alcohol, 2-butyl alcohol, and 3-methyl-2-methyl alcohol.
Examples thereof include pentyl alcohol and 3-hexyl alcohol, and are preferably secondary alcohols, and particularly preferably isopropyl alcohol, 2-butyl alcohol, and 3-hexyl alcohol.

The aluminum alcoholate used in the present invention may be any, but preferably has 1 to 1 carbon atoms.
Those having an alcoholate of 5, for example, aluminum trimethylate, aluminum triethylate, aluminum tripropylate, aluminum triisopropylate, aluminum tributyrate, aluminum triisobutyrate, sec-butoxyaluminum diisopropylate, etc. Can be In particular, aluminum triisopropylate, sec-butoxyaluminum diisopropylate, and aluminum triisopropylate are most preferred in terms of yield.

In the process of the present invention, the aluminum alcoholate is preferably used in an amount of 0.1 to 0.5% for α, β-unsaturated aldehyde.
It is used in the range of 5 to 35 mol%, more preferably 1 to 25 mol%.

In the method of the present invention, the addition amount of the primary or secondary alcohol having 2 to 8 carbon atoms is preferably 0.7 to 15 mol times, more preferably 1 to 10 mol times, relative to the α, β-unsaturated aldehyde. preferable.

As the protonic acid used in the present invention, trichloroacetic acid, dichloroacetic acid, chloroacetic acid, trifluoroacetic acid,
Difluoroacetic acid, haloacetic acid such as fluoroacetic acid, hydrochloric acid,
Mineral acids such as sulfuric acid, hydrocarbon sulfonic acids such as trifluoromethanesulfonic acid, paratoluenesulfonic acid and methanesulfonic acid, acetic acid, lower aliphatic carboxylic acids such as propionic acid, etc., and strong acids such as trichloroacetic acid and trifluoroacetic acid. Acetic acid, sulfuric acid, and methanesulfonic acid are preferred, and trichloroacetic acid and sulfuric acid having a high boiling point are preferred because they do not volatilize even at high temperatures.

In the method of the present invention, the protonic acid is preferably used in an amount of 0.005 to 30 mol% based on the α, β-unsaturated aldehyde.
More preferably, 0.01 to 10 mol% is used.

In the present invention, the reaction is carried out at a reaction temperature of 0 to 150 ° C., preferably 10 to 120 ° C., and the reaction is preferably carried out while distilling off a carbonyl compound such as acetone derived from a lower alcohol produced by the reaction. Further, in the present invention, it is particularly preferable to carry out the reaction while distilling off the carbonyl compound produced by the reaction using trichloroacetic acid having relatively high boiling point and sulfuric acid. More preferably, it is performed.

The solvent is not always necessary, but if necessary, an inert solvent such as toluene or xylene may be used.

In the method of the present invention, an unsaturated alcohol is efficiently produced from an α, β-unsaturated aldehyde by using a smaller amount of a primary or secondary alcohol having 2 to 8 carbon atoms and aluminum alcoholate as compared with the conventional method. can do.

The desired product can be easily separated from the reaction mixture by a conventional method such as precision distillation followed by decomposition of aluminum alcoholate with an acid.

Examples Hereinafter, the present invention will be described in more detail with reference to Examples.
The present invention is not limited to these examples.

Example 1 Aluminum isopropylate [Al (Oi-Pr) ₃ ] 2.04 (10 mm
ol) and 10 ml of toluene and stirring at room temperature, while stirring 2-methyl-4- (2,2,3-trimethyl-3-cyclopenten-1-yl) -2-buten-1-al 9.6. g
(50 mmol), followed by trifluoroacetic acid 0.17 (1.5 m
mol) and 3.0 g (50 mmol) of isopropyl alcohol
Was added thereto, followed by stirring at room temperature. After 5 hours, analysis by GLC showed that 2-methyl-4- (2,2,3-trimethyl-3-cyclopenten-1-yl) -2-buten-1-.
62% of all was formed (this corresponds to a selectivity of 85% with respect to the conversion of the starting aldehyde).

Rate).

 It had a clear strong sandalwood-like aroma.

Example 2 Instead of trifluoroacetic acid, 0.25 g of trichloroacetic acid
(1.5 mmol), and the reaction was carried out in the same manner as in Example 1. After 5 hours, the reaction was analyzed by GLC.
-(2,2,3-trimethyl-3-cyclopenten-1-yl) -2-buten-1-ol was formed at 61% (this has a selectivity of 87% based on the conversion of the starting aldehyde). Equivalent).

 It had a clear strong sandalwood-like aroma.

Example 3 A reaction was carried out in the same manner as in Example 1 except that toluene was not added. After 5 hours, the reaction was analyzed by GLC.
4- (2,2,3-trimethyl-3-cyclopentene-1-
67% of yl) -2-buten-1-ol was produced (this corresponds to a selectivity of 91% with respect to the conversion of the starting aldehyde).

 It had a clear strong sandalwood-like aroma.

Example 4 2.18 g (10 mmo) of sec-butoxyaluminum diisopropylate instead of aluminum isopropylate
l), instead of 2-ethyl-4- (2,2,3-trimethyl-3-cyclopenten-1-yl) -2-buten-1-al, 2-ethyl-4- (2,2,3- Trimethyl-3-cyclopenten-1-yl) -2-buten-1-al
The reaction was carried out in the same manner as in Example 1 except that 10.3 g (50 mmol) was used, and after 5 hours, it was analyzed by GLC.
4- (2,2,3-trimethyl-3-cyclopentene-1-
60% of yl) -2-buten-1-ol was produced (this corresponds to a selectivity of 87% with respect to the conversion of the starting aldehyde).

 It had a clear sandalwood-like odor.

The reaction was conducted in the same manner as in Example 1 except that trifluoroacetic acid was not added. After 5 hours, the reaction was analyzed by GLC. As a result, 2-methyl-4- (2,2,3-trimethyl-3-cyclopenten-1-yl) was obtained. -2-buten-1-ol was produced at 2%.

Example 5 Al (O—
While adding 3.07 g (15 mmol) of i-Pr) _{3 and} 30 ml of toluene and stirring at room temperature, 2-methyl-4- (2,2,3-
28.8 g (150 mmol) of trimethyl-3-cyclopenten-1-yl) -2-buten-1-al were added, followed by 0.25 g (1.5 mmol) of trichloroacetic acid and 18.0 g (300 mmol) of isopropyl alcohol. Solution temperature 80 ° C to 92 ° C
The reaction was carried out while distilling off the fraction containing acetone generated in the above. After 6 hours, the reaction solution was analyzed by GLC, and it was found that 2-methyl-4- (2,2,3-trimethyl-3-cyclopentene-1- 81% of yl) -2-buten-1-ol was produced (this corresponds to a selectivity of 90% with respect to the conversion of the starting aldehyde). ◇ It had a clear strong sandalwood-like aroma.

Example 6 The amount of aluminum isopropoxide was adjusted to 1.02 g (5 mmo).
l) The reaction was carried out in the same manner as in Example 3 except that the amount of trifluoroacetic acid was reduced to 0.06 g (0.5 mmol).
As a result, 2-methyl-4- (2,2,3-trimethyl-3-cyclopenter-1-yl) -2-butene-
40% of 1-ol was formed (this corresponds to a selectivity of 93% with respect to the conversion of the starting aldehyde).

Example 7 A reaction was carried out in the same manner as in Example 6 except that the reaction temperature was changed to 60 ° C. After 5 hours, the product was analyzed by GLC.
55% of-(2,2,3-trimethyl-3-cyclopenten-1-yl) -2-buten-1-ol was produced (this has a selectivity of 83% with respect to the conversion of the starting aldehyde). Equivalent).

Example 8 A reaction was carried out in the same manner as in Example 7 except that 0.05 g (0.5 mmol) of sulfuric acid was used instead of trifluoroacetic acid.
When analyzed by C, 2-methyl-4- (2,2,3-trimethyl-3-cyclopenten-1-yl) -2-butene-
58% of 1-ol was formed (this corresponds to a selectivity of 85% with respect to the conversion of the starting aldehyde).

Example 9 Methanesulfonic acid 0.05 g instead of trifluoroacetic acid
(0.5 mmol), and the reaction was conducted in the same manner as in Example 7. After 5 hours, the reaction was analyzed by GLC.
54% of (2,2,3-trimethyl-3-cyclopenten-1-yl) -2-buten-1-ol was produced (this resulted in a selectivity of 85% with respect to the conversion of the starting aldehyde). Equivalent to).

Example 10 A reaction was carried out in the same manner as in Example 6 except that 3.7 g (50 mmol) of 2-butanol was used instead of IPA. After 5 hours, the product was analyzed by GLC. As a result, 2-methyl-4- (2,2, 3-trimethyl-3-cyclopenten-1-yl) -2-butene-1
-45% of all was formed (corresponding to a selectivity of 94% with respect to the conversion of the starting aldehyde).

Example 11 Instead of IPA, 4.4 g of 3-hexyl alcohol (50 mmo
The reaction was carried out in the same manner as in Example 6 except that l) was used, and after a lapse of time, analysis by GLC revealed that 2-methyl-4- (2,2,3-trimethyl-3-cyclopenten-1-yl) -2 -Buten-1-ol was produced by 48% (this corresponds to a selectivity of 94% with respect to the conversion of the starting aldehyde).

Example 12 Al (O-
i-Pr) ₃ 10.2 g (50 mmol), sulfuric acid 0.25 g (2.5 mmol), IP
A180 g (3.0 mmol) was added, and the mixture was stirred at 85 ° C., and the mixture was stirred at 2-methyl-4- (2,2,3-trimethyl-3-cyclopenten-1-yl) -2-buten-1-. Earl 192g
(1.0 mol) was added. The reaction was carried out while distilling off a fraction containing acetone generated at a solution temperature of 85 ° C to 95 ° C. After 7 hours, the reaction solution was analyzed by GLC.
88% of (2,2,3-trimethyl-3-cyclopenten-1-yl) -2-buten-1-ol was produced (this resulted in a selectivity of 92% with respect to the conversion of the starting aldehyde). Equivalent to).

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Junko Yamamoto 1334 Minato, Wakayama City, Wakayama Prefecture Kao Corporation Laboratory (56) References JP-A-55-139330 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C07C 33/00 C07C 29/132

Claims (11)

(57) [Claims] 1. An α, β-unsaturated aldehyde having 2 carbon atoms
(1) an unsaturated alcohol produced by selectively reducing an aldehyde group using an aluminum alcoholate in the presence of a primary or secondary alcohol to produce an unsaturated alcohol; A method for producing alcohol. 2. An α, β-unsaturated aldehyde of the formula (I) 2,2,3-trimethyl-3-cyclopentene represented by
The method according to claim 1, which is a compound having a 1-yl group. 3. An α, β-unsaturated aldehyde of the formula (II) (In the formula, R represents an alkyl group having 1 to 3 carbon atoms.) 2-alkyl-4- (2,2,3-trimethyl-
3-cyclopenten-1-yl) -2-buten-1-al, wherein the unsaturated alcohol is of the formula (III) (Wherein, R represents the above-mentioned meaning.) 2-alkyl-4- (2,2,3-trimethyl-
The production method according to claim 1, which is 3-cyclopenten-1-yl) -2-buten-1-ol. 4. The method according to claim 3, wherein R is a methyl group or an ethyl group.
Production method described in 1. 5. The method according to claim 1, wherein the aluminum alcoholate is aluminum tri-isopropylate or sec-butoxyaluminum diisopropylate. 6. The method according to claim 1, wherein the protonic acid is trichloroacetic acid, trifluoroacetic acid, methanesulfonic acid or sulfuric acid. 7. The process according to claim 1, wherein the reaction is carried out while distilling off a carbonyl compound derived from a primary or secondary alcohol having 2 to 8 carbon atoms produced by the reaction. 8. The primary or secondary alcohol having 2 to 8 carbon atoms is isopropyl alcohol, 2-butyl alcohol, or 3-butyl alcohol.
The production method according to claim 1, wherein the production method is hexyl alcohol. 9. The method according to claim 1, wherein said α, β-unsaturated aldehyde is 0.7 to 1%.
5 mole times primary or secondary alcohol having 2 to 8 carbon atoms,
In the presence of 0.5 to 35 mol% of aluminum alcoholate based on α, β-unsaturated aldehyde and 0.005 to 30 mol% of protic acid based on α, β-unsaturated aldehyde,
The method according to claim 1, wherein an α, β-unsaturated aldehyde is used. 10. The protic acid is formed from trichloroacetic acid, dichloroacetic acid, chloroacetic acid, trifluoroacetic acid, difluoroacetic acid, fluoroacetic acid, hydrochloric acid, sulfuric acid, trifluoromethanesulfonic acid, paratoluenesulfonic acid, methanesulfonic acid, acetic acid and propionic acid. The method according to claim 1, wherein the method is selected from the group consisting of: 11. The process according to claim 1, wherein the protonic acid is selected from the group consisting of haloacetic acids, mineral acids, hydrocarbon sulfonic acids and lower aliphatic carboxylic acids.