DE1768099B - Process for the preparation of 1 alkene 5 ons and 1 alkene 5 alene - Google Patents

Description

R ¹

in which R ¹ , R ² and R ³ denote hydrogen or aliphatic hydrocarbon radicals with 1 to 40 carbon atoms, which are connected in pairs to form 5- to 7-membered rings and can contain the oxygen atoms as heteroatoms and in which R ⁴ denotes hydrogen or a hydrocarbon radical with 1 to 40 carbon atoms, which can also contain oxygen atoms as heteroatoms, characterized in that an allyl alcohol of the general formula

R ¹ R ³

\ I

CC = CH ₂

/ I

R ² OH

(H)

at temperatures between 50 and 35O ° C in a molar ratio of 1: 5 to 5: i with an acylmalonic ester of the general formula

Il

R-O-C O

CH-CR ⁴ (III)
R '-Ο-C
O

in which the radicals R 'are identical or different alkyl groups with 1 to 8 carbon atoms, in liquid phase and the intermediate products obtained of the general formula

R ¹

R ³

Il

R ²

= C-CH ₂ -CH-CR ⁴ (IV)
COOR '

Immediately or after prior isolation, subjecting them to a ketone cleavage by either treated with acids directly or after alkaline saponification of the - COOR 'group.

There has been a process for the preparation of l-alken-5-ones and l-alken-5-ales of the general Formula I.

R ¹

R ³ O

: = c - CH ₂ - CH ₂ - c - R ⁴

(I)

Molar ratio from 1: 5 to 5: 1 with an acyl malonic ester of the general formula III

40

R'-O-C

CH - C - R ⁴

(III)

in which R ', R ² and R ³ denote hydrogen or aliphatic hydrocarbon radicals with 1 to 40 carbon atoms, which are connected in pairs to form 5- to 7-membered rings and which can contain oxygen atoms as heteroatoms, and in R ⁴ hydrogen or a Hydrocarbon radical with 1 to C atoms, which can also contain oxygen atoms as heteroatoms, found that is characterized by i? » that an allyl alcohol of the general formula H

R-O-C

so in which the radicals R 'are identical or different alkyl groups with 1 to 8 carbon atoms, in liquid phase and the intermediate products obtained of the general formula IV

R '

\ I

R ¹ R ³

R ¹ OH

with kettle temperatures between 50 and 3 OK ° C in one

60 = C-CH ₂ -CH-CR ⁴ (IV)
COOR '

Immediately or after prior isolation, subjecting them to a ketone cleavage by either directly or after alkaline saponification of the - COOR 'group treated with acids.

Individual representatives of the class of compounds defined by formula I are known, but only naqh special, non-generalizable methods are available in mostly inadequate yields.

The hydrocarbon ^{radicals R 1} , R ² and R ³ can be branched or unbranched, saturated or unsaturated aliphatic radicals or cycloaliphatic radicals. By definition, these radicals can contain oxygen as heteroatoms, namely as hydroxyl or carboxyl groups or in ether, ketone, ester or epoxy groups.

Allyl alcohol II suitable as starting material are allyl alcohol itself, l-butene-S-ol ^ ethyl-l-octen-3-ol, 1-vinyl-cyclohexan-l-ol, linalool, nerolidol, isophytol, 3-phenyl-1-propene - 3 - oil and 3 - methy! l-penten-3-ol.

Starting compounds II in which R ^{1 is} a methyl group, R * is hydrogen and R ^{2 is} a group of the general formulas are of particular importance for syntheses in the field of vitamins and fragrances

H -j- CH ₂ - CH - CH ₂ - CH ₂ CH ₃

CH, -

- CH, - C - Ch ₂ - CH,

"Il

CH,

CH, -

H -

CH ₂ - C = Cri - CH ₂ CH ₃

CH ₂ -

where η is an integer from 1 to 8

The acylmalonic esters III are simple by reacting z. B. Sodium or magnesium ^{malonic esters with acid chlorides R 4} —CO — Cl (V) are available. Examples of suitable radicals R ⁴ in the compounds III and V are the formyl, acetyl, propionyl, isobutyroyl, benzoyl, / i-hydroxypropionyl and the / i-methoxyacryloyl group.

The compounds II and III react with one another in stoichiometric amounts, but it is often advisable to use the cheaper component in an approximately up to 5-fold stoichiometric excess, ie in a molar ratio of 5: 1 to 1: 5, in order to achieve the most complete conversion possible.

The reaction is preferably carried out at temperatures between 50 and 350 ° C., particularly between 110 and 190 "C, before, with or without solvents or diluents and at Printing between 100 Torr and 10 at, but usually at normal pressure.

Suitable solvents or diluents for this reaction are inert liquids, including above all high-boiling hydrocarbons such as perhydro- and tetrahydronaphthalene, dimethylformamide and N-methylpyrrolidone.

Since carbon dioxide is split off in addition to the alcohol ROH in the reaction of Π with III the end of which is easy to determine.

The immediately available intermediates IV au9 II and ItI can be prepared by the customary methods, e.g. B. by distillation, isolated from the reaction mixture oder'äiuch are preferably subjected to nuclear fission without isolation.

For nuclear fission, IV or the IV-containing reaction mixture is left for about 5 to 120 minutes at 50 to 100 ^° C. with 1 to 5 mol percent, based on the amount of IV, of an acid _: such as sulfuric acid, hydrochloric acid, phosphoric acid or acetic acid, at pH -Value between about 1 and 3 react, after which

The process product I is isolated as usual. The two-stage nuclear fission is often preferred, by first saponifying the —COOR “group of IV under alkaline conditions and then in an acidic medium the real split.

The claimed process, which can also be carried out continuously with particular advantage by the methods known for this purpose, a large number of l-alken-5-ones, (- /, Λ-unsaturated ketones) and l-alken-5-alen ( - /, η-unsaturated aldehydes) accessible in a simple and universally applicable manner. The products of the process either have excellent fragrance properties themselves , or they are valuable starting materials for a number of organic syntheses.

The following percentages are units of weight.

example 1 Phenyl (4-methyl-3-hexen-1-yl) ketone

264 g (1 mol) of diethyl benzoylmalonate are gradually added at 175 to 180 ° C. with HOg (1.1 mol) 3-methyl-1-penten-3-ol, with the resulting ethanol running out of the reaction mixture Will get removed. After about 3 hours, when no more carbon dioxide is evolved, add 500 ml Add 20% sodium hydroxide solution and add 100 ml of ethanol to the reaction mixture to produce a homogeneous solution, and heat it to 80 ° C. for 2 hours then acidify it at 40 C with 10 n sulfuric acid to pH 1.

When the elimination of carbon dioxide has ended, the process product is isolated as usual by extraction and distillation.

The abovementioned ketone is obtained in a 74% yield; _{Bp 101005} == 94 to 95 ° C; η'ί = 1.5226.

Example 2 2,7,1 l-trimethyl-o.lO-dodecadienO-one

Obtained in the manner described in Example 1

one from 23Og (1 mol) isobutyroylmalonic acid diethyl ester and 169 g (1.1 moles) of linalool the above

Ketone in 77% yield; Bp _M01 = 83 to 85 ° C;

n ^? "'" 1.4640.

Example 3 7-methyl-6-nonen-3-one

In the manner described in Example I, the abovementioned ketone is obtained in 71% yield from 216 g (1 mot) of diethyl propionylmalonate and 110 g of 3-methyl-1-penten-3-ol; Bp. ₁₀ => 91 to i93 ° C; ni? = 1.4440.

Example 4 6,10-dimethyl-5,9-undecadien-2-one (geranylacetone)

In the manner described in Example 1, 202 g (1 mol) of diethyl acetylmalonate and 169 g (1 mol) of linalool give geranylacetone in 74% yield; _{B.p. 05} = 112 to 119 ° C; n ^! " ^S = 1.4670.

Example 5
o-Cyclohexylidenhexan ^ -one

108 g (0.5 mol) of Propionylmalonsäurediätliyltister at 150 to 180 C for about 1 hour with 69 g (0.55 mol) of 1-vinylcyclohexan-l-ol to react, the mixture is then treated with 300 ml of 20% sodium hydroxide solution and 100 ml of methanol and heat it up! Sturfde long at 80C. It is then acidified at 60 "C with 30% sulfuric acid to pH 1 and then worked up to the desired process product. The abovementioned ketone is obtained in 72% expansion; bp ₀₀ " = 66 to 68 ° C; n ? = 1.4777.

Example 6
7-ethyl-5-undecaen-2-one

In the manner described in Example 5, 110 g (0.5 mol) of diethyl acetylmalonate and 78 g (0.55 mol) of 4-ethyl-1-octen-3-ol give the abovementioned ketone in 76% yield; _{Bp 0} , = 60 to 62 ° C; n ' _o ' = 1.4431.

Example 7
o.lO-Dimethyl-lO-methoxy-S-undecaen ^ -one

186 g (1 mole) 3,7-dimethyl-7-methoxy -1-octen-3-ol and 303 g (1.5 mol) of acetylmalonic acid diethyl ester are heated with stirring. The reaction temperature is in the course of the implementation of initially increased from 120 to 175 "C. After about an hour, the alcohol and carbon dioxide are split off completed, and the reaction mixture can be fractionally distilled.

In addition to a little starting material, the distillation gives 225 g of 6,10-dimethyl-10-methoxy-3-carbethoxy-5-undecaen-2-one; Kp = _{0 5} 133 to 136 ° C; "i - = 1.4582.

To cleave the ketone, this product is added to a solution of 80 g of sodium hydroxide in 500 ml of water, alcohol is added until it is completely dissolved and the mixture is ^{heated to 70 to 80 °} C. for 1 hour. It is then acidified to pH 1 at 40 to 50 ° C. with 40% strength sulfuric acid and worked up in the usual way. In the distillation, the process product is obtained in a yield of 75%; Bp _0. , = 85 to 88 "C;n'J = 1.4553.

Example 8

ö.lO-Dimethyl-lO-hydroxy-S-undecaen ^ -one
In the manner indicated in lead example 7, one obtains

Example 9

7,10-dimethyl-6,10-dodecadien-3-one-1-carboxylic acid

152 g (1 mol) of linalool and 356 g (I ₁ J MoIj!, 1-Dicarbäthoxy-4-carbmethoxybutan-2 "are reacted at 160 to 200 ⁰ C within about 45 minutes on. After the completion of alcohol and elimination of carbon dioxide is the reaction mixture is subjected to ketone cleavage and worked up in the usual manner as described in Example 7. The process product is obtained in a yield of 64%; b.p. 0.03 = 152 to 155 ° C.; melting point = 35 ° C.

At spie! 10

- 1-al

77 g (0.5 mol) of linalool, ad 113 g (0.6 mol) of formylmalonic acid diethyl ester are reacted at 120 to 165 ° C within about 60 minutes. After the elimination of alcohol and carbon dioxide has ended, the reaction mixture is distilled. In addition to starting material, this gives 90 g of 5,9-dimethyl-2-carbethoxydeca-4,8-diene-1 sals; Kp _{0 s} = 112 to 115 ^G C; n? = 1.4746.

When this product is cleaved in the usual way, the 5,9-dimethyldeca-4,8-dien-1-al is obtained in a yield of 40%; Bp ₀ ,, == 92 to 96 ° C; ni ^! = 1.4997.

Example 11

2,3-dimethyl-2-octene-6-cin

In the manner described in Example 1, 216 g (1 mol) of diethyl propionylmalonate and HOg (1.1 mol) of 2,3-dimethy! -L-bivten-3-ol ^ -Di-SS methyl-2-octen- 6-one in 71% yield; _{Bp n} 92 to 96 ° C; ni ⁵ = 1.4445.

Example 12 2,2,7,1 i, 15,19-hexamethyl-6-dco! Aen-3-one

81 g of isophytol (0.27 mol) and 100 g Pivaloylmalonester (0.41 mol) of 1.5 hours to 175 to 180 ⁰ C are heated. After this, the elimination of alcohol and carbon dioxide has ended. The reaction mixture is mixed after cooling with 205 ml of 20% NaOH and 50 ml of alcohol and heated with stirring for 2 hours at 8O ⁰ C. Thereafter, the mixture is acidified with LON sulfuric acid at 20 to 30 ⁰ C, and again carbon dioxide is released. The organic phase is then isolated by extraction with ether and, after washing with soda solution and water, xlessilled. 52 g of the abovementioned ketone are obtained. This corresponds to a yield of 51 % of theory; _{Bp 0} 02 150 to 154 ° C; n'n> = 1.4f08.

Example 13

2,2,7,1 U.S. ^ - Hexamethyl-o.lO.H.lS-eicosatetraen-3-one

In the manner described in Example 12 are

from 172 g (1 mol) 3,7-dimethyl-l-octene-3,7-diol and 60 from 81g geranyllinalool and 100 g pivaloylmalon

242 g (~ 1.2 mol) of diethyl acetylmalonate are the desired process product in a yield of 72%; Kp _o . ₀₈ = 115 to 117 ° C; nl> = 1.4660. ester 49 g of the above ketone obtained. The yield is 48% of theory; Kp ₀₀₀₇ 150 to 164 ⁰ C. ηέ? = 1.4943.

Claims (1)

Claim: Process for the preparation of l-alken-5-ones and l-alken-5-alene of the general formula R ¹ R ³ I. c- CH ₂ -CH ₂ -CR ⁺ (I)