DE2509576C3 - Process for the preparation of α, ß-unsaturated γ-lactone derivatives - Google Patents

Description

where Ri is an alkyl group with 1 to 4 carbon atoms, R _{2 is} an alkyl group with 1 to 4 carbon atoms or an alkylene group with 2 to 20 carbon atoms and R _{3 is} a hydrogen atom or an alkyl group with 1 to 4 carbon atoms, characterized in that a 2 -Alkine-1,4-diol of the general formula

R ₁ R ₂

HO-C-C = C-C-OH

ι t

CH ₃ CH ₃

(ID

in which R ₁ and R _{2 have} the meaning given above, with an orthoacetic acid ester of the general formula

R.3 CH2

OR ₄

OR ₆

(ΙΠ)

in which R3 has the meaning given above and R «, R5 and Rb each represent an alkyl group with 1 to 8 carbon atoms or a cycloalkyl group with λ to 10 carbon atoms, where R4, Rs and Re can be the same or different, in the presence of a phenol, a fatty acid having 2 to 6 carbon atoms, an aromatic carboxylic acid, mineral acid or sulfonic acid as the acidic catalyst, which is used in an amount of 0.001 to 20% by weight, based on the weight of the starting compound (II), at a temperature of about 100 to 250 ° C converts.

The invention relates to a process for the preparation of γ-unsaturated γ-lactone derivatives of the general formula

C = CH-C

^CHi

C-CH ₃
O

wherein Ri is an alkyl group having 1 to 4 carbon atoms, R _{2 is} an alkyl group having 1 to 4 carbon atoms or an alkenyl group having 2 to 20 carbon atoms and Rj is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, which is characterized in that one 2-alkyne-1,4-diol of the general formula

HO-C-C = C-C-OH

CH ₃

CH ₃

in which R ₁ and R _{2 have} the meaning given above, with an orthoacetic acid ester of the general formula

OR ₄

R ₁ -CH ₂ -C-OR ₅
OR ₆

(III)

in which R 3 has the meaning given above and R4, R5 and R6 each represent an alkyl group of 1 to 8 Represent carbon atoms or a cycloalkyl group having 3 to 10 carbon atoms, wherein R4, R5 and Ri, can be the same or different, in the presence a phenol, a fatty acid with 2 to 6 carbon atoms, an aromatic carboxylic acid, mineral acid or sulfonic acid as the acidic catalyst, in an amount of 0.001 to 20% by weight, based on the Weight of the starting compound (II) is used at a temperature of about 100 to 250 ° C implements.

So far, for the production of lactone derivatives, the lactone derivatives to be produced according to the invention have been used are similar, the following methods are known:

That described in Journal of the American Chemical Society, Vol. 89, pp. 3850-3857 (1967) The method is based on 2,4,6-tri-t-butyl-4-methoxy-2,5-cyclohexadienone, which is subjected to photolysis and wherein a variety of photolysis products are formed. From a certain such The product, a dicyclopentanone, is obtained by pyrolysis of various unsaturated lactones.

The disadvantages of this process are that the photolysis and pyrolysis are inconsistent that it is expensive and the yield of the lactone is low.

According to one described in the Journal of the American Chemical Society, Volume 94, pages 4395-4396 (1972) Method is using a similar lactone in a multi-step complicated process of expensive reagents such as n-BuLi and

, 5 (CH ₂ = CH) ₂ CuLi. This method, too, therefore has considerable disadvantages.

According to the method according to the invention it is now possible in a very simple manner in one step from easily available starting materials the relevant «^ -unsaturated γ-lactones in very good yields to manufacture.

The following are particularly suitable as starting compounds of the general formula (II):

fts 2,5-dimethyl-3-hexyne-2,5-diol,
3,6-dimethyl-4-octyne-3,6-diol,
2,4,7,9-tetramethyl-5-decyne-4,7-diol and
2,5,7-trimethyl-3oclin-2,5-diol.

As 2-substituted orthoacetic acid ester compounds of the general formula (III) the following compounds may be mentioned:

-Trimethoxyethane,

-Triethoxyethane,

-Tripropyloxyethane,

-Tricyclohexyloxyethane,

-Tri- (n-butyloxy) -ethane,

-Triethoxypropane,

-Triethoxybutane,

-Triethoxypentane,

S-methyl-III-triethoxybutane,
2-CycIohexyl-1,1,1 -triinethoxyäthan,

, 1-dimethoxy-1-cyclohexyloxyethane and

, 1-dimethoxy-1-pentoxyethane.

Suitable acidic catalysts are, for example, phenolic compounds such as

Phenol, o-, m- or p-nitrophenol, o-, m- or p-cresol, o-, m- or p-xylenol,
2,6-dimethylphenol, 2,6-di-tert-butylphenol,
2,4,6-tri-sec-butylphenol,
2,4,6-tri-tert-butylphenol,

4-methyl-2,6-di-tert-butylphenol, 4-methyl-3,5-di-tert-butylphenol,
Hydroquinone, 2,5-di-tert-butylhydroquinone,
also lower fatty acids, for example acetic acid, propionic acid, butyric acid, isobutyric acid, cyclohexanecarboxylic acid, valeric acid, malonic acid, succinic acid, adipic acid and aromatic carboxylic acids such as benzoic acid, m-chlorobenzoic acid and sulfonic acids such as benzenesulfonic acid, p-toluenesulfonic acid. Suitable mineral acids are, for example, hydrochloric acid, sulfuric acid, phosphoric acid, boric acid. In order to avoid dehydration of the diol of the formula (II) or other side reactions, it is particularly advantageous to use phenols, aromatic carboxylic acids or fatty acids which contain 2 to 6 carbon atoms. The amount of the acidic catalyst used varies between 0.001 and 20% by weight and is preferably between 1 and 15% by weight, based on the weight of the starting compound (II).

A solvent is not necessary for carrying out the process according to the invention, but an inert solvent, for example
n-heptane, n-octane, toluene, o-,
ro- or p-xylene, di-n-butyl ether,
terL-butanol or N, N-dimethylformamide
be used.

The orthoacetic acid ester can be used in excess so that it also serves as a solvent

The course of the reaction of the process according to the invention probably takes place in such a way that the Reaction via a ketene / acetal complex in a transition state to a 6-membered ring and an ester of siner hydroxyallene carboxylic acid as intermediate compounds according to the following scheme expires:

OR ₆

[II] + [III]
H ⁺ / 1

-R ₄ OH ₁ -R ₅ OH

-R ₆ OH [I]

As a result of dealcoholization in an equilibrium system, as shown in the above equation As can be seen, the alcohol formed as a by-product during the reaction becomes preferably continuous driven out of the reaction system.

These process products are suitable, for example, as intermediates for the synthesis of chrysanthemum monocarboxylic acids and their esters, which are insecticides, as well as for the synthesis of non-isoprenoid Terpene alcohols.

Of the compounds of the general formula (I), the one in which R ₁ and R 2 denote the methyl group and R 3 denotes a hydrogen atom represents the "J3-dehydropyrocin" and from which the pyrocinol can easily be prepared by selective reduction of the ", /? Double bond can. The pyrocin has an insecticidal activity. From this compound, in turn, chrysanthemum monocarboxylic acid and non-isoprenoid terpene alcohols can be prepared ("gl. W. Su crow, W. Richter," Tetrahedron Leiters 1970 ".

No.42, 3675 and M. Uchiyama, M. Matsui, »Agr. Biol. Chem. ", 26, No. 8,532 [1962]).

In the following examples, all parts of the data relate to weight. Unless otherwise is indicated, the NMR spectra are in carbon tetrachloride at 60 MHz and at room temperature measured using tetramethylsilane as an internal standard. In the case of the NMR values, means the symbol (s) a singlet, (bs) a broad singlet, (t) a triplet, (m) a multiple and (J) a coupling constant.

example 1

At a reaction temperature between 140 and 15O ⁰ C 14.2 parts of 2,5-dimethyl-3-hexyne-2,5-diol, 32.4 parts of Triäthylorthoacetat stirred and 1.4 parts of phenol together with the ethanol formed as a by product is continuously distilled off. After 24 hours the reaction mixture is distilled directly under reduced pressure. The Kd.

0.07 / 92 to 94 ° C. The upper fraction represents the «, ^ - unsaturated j ^ lactone of the formula

C = HC-C

/ Il

H ₃ C HC

-C

O CH ₃ parts phenol are used. The γ-unsaturated γ-lactone of the formula is obtained

C = HC-C-

/ Il

H ₃ CH ₃ CC

l \

O CH ₃

The yield is 91%. This connection has the following properties:

Melting point:

62 to 62.5 ⁰ C
NMR spectrum o (ppm):

142 (s) 6H, 2.00 (bs) 6H, 5.68 (bs) 2H
IR spectrum (NujoJ) r

1734cm - '(> C = O)

in a yield of 96%.

The connection has the following properties:

Bp 0.07:

82 to 84 ° C
Nuclear Magnetic Resonance Spectrum (d, ppm):

1.36 (sh) 6H; 1.66 (bs) 6H; 1.95 (bs) 3H; 5.66 (bs) 1H IR spectrum (pure):

I753cm -! (> C = O)

Example 2

1.4 parts of isobutyric acid are added in small portions to a mixture of 14.2 parts of 2,5-dimethyl-3-hexyne-2,5-diol and 32.4 parts of triethyl orthoacetate. The mixture is heated with constant stirring to 12 hours on 130 to 14O ⁰ C. The ethanol formed as a by-product is continuously expelled from the reaction system 30 H ₃ C star. The reaction mixture obtained is then distilled off directly as described in Example 1 under reduced pressure. The α, β-unsaturated γ-lactone given in H ₃ C Example 1 is obtained in a yield of 81%. ^

Example 5

The procedure described in Example 1 is repeated, but using 2.1 parts of 2,5,9-trimethyldesa-8-en-3-yn-2,5-diol, 3.2 parts of triethyl orthoacetate and 0.1 part of isobutyric acid are used. You get that «, / J-unsaturated γ-lactone of the formula

Example 3

The procedure described in Example 1 is repeated, except that 10 parts of 3,6-dimethyl-4-octyne-3,6-diol, 19.0 parts of triethyl orthoacetate and 1.0 part of phenol are used. The "^ -unsaturated" is obtained y-lactone of the formula

CH,
C = HC-C C CH ₃

Il \ /

f ^ i ^. ~ CH ₂ CH ₂ -CH-C

LU \

\ / CH ₃

Il O

H, C

CH ₃

C = HC-C-

/ Il

H ₅ C ₂ HC ₁

45

I \
OC ₂ H,

O
in a yield of 95%.

The connection has the following properties:

Bp 0.07:

104 to 05 ° C
NMR spectrum (<5, ppm):

0.74 (t, J = 7 cps) 3 H; 1.11 (t, J = 7 cps) 3 H;

1.5-1.9 (m) 2H, 1.98 (s) 3H; 2.0-2.4 (m) 2H; 5.70 (bs)

2H
IR spectrum (pure):

1745cm-> (> C = O)

Example 4

The procedure described in Example 1 is repeated, except that 4.8 parts of 2,5-dimethyl-3-hexyne-2,5-diol, 12.0 parts of triethyl orthopropionate and 0.5 parts in a yield of 76%.
The connection has the following properties:

Bp 0.2:

92 to 96 ° C
IR spectrum (pure):

1745cm - '(> C = O)
Nuclear Magnetic Resonance Spectrum (O ppm):

1 _f 42 (s, 3 H), 1.65 (m, 6 H), 1.98 (m, 6 H), 5.0 methyl signals:

5.05 (m, 1H), 5.65 (m, 1H), 5.80 (1H) ^ ₀ olefinic signals.

Example 6

The procedure described in Example 1 is

repeated except that 5.5 parts of 2,5-dimethyl-3-nonyne-2,5-diol, 9.7 parts of triethyl orthoacetate and 0.3 part of isobutyric acid are used. The / x, jj-unsaturated y-lactone of the formula is obtained

H ₃ C

Η, Γ

C ₄ H,

C = HC-C-

—C

HC

O CH ₃

in a yield of 60%.

The connection has the following properties:

Bp 0.2:

103 to 108 ⁰ C
IR spectrum (pure):

1745cm - '(> C = O)
NMR spectrum (δ ppm):

1.99 (m, 6H) methyl signal; 5.66 (m, 1H),

5.80 (s, 1H) olefinic signals.

identical to that of example 1. The respective yields can be found in Table I:

Table I.

Example acid catalyst

Yield to

α, / J-unsaturated

)> - lactone

Examples 7 to 12

The procedure described in Example 1 is repeated with the exception that the acid catalyst instead of phenol, the compounds given in Table I below are used. The obtained «, ^ - unsaturated γ-lactone is with

7 cyclohexanecarboxylic acid 95

8 adipic acid 91

9 benzoic acid 87

10 p-toluenesulfonic acid 65

11 phosphoric acid 62

12 hydroquinone 93

Claims (1)

Claim: Process for the production of «^ -unsaturated y-lactone derivatives of the general formula CH ₃ C = CH-C- -C-CH ₃
O