DE1021360B - Process for the preparation of polyene aldehydes with 19 carbon atoms - Google Patents

Description

GERMAN

to the

The invention relates to a method
Production of polyene aldehydes with 19 carbon atoms. The process is characterized in that acetylene is converted in a known manner by an organometallic reaction on the one hand with a methylglyoxal _{acetal and on the other hand with a C 14} aldehyde of the general formula

R-CH = C-CHO

CH ₃

in which R is a hydrocarbon radical with the carbon structure of Cyclogeraniol, condenses that formed condensation product treated in a known manner with excess lithium aluminum hydride and then hydrolyzed in the usual way in acidic solution.

Of already known processes for the production of polyene aldehydes with 19 carbon atoms (cf. e.g. Liebigs Annalen der Chemie, Vol. 588, 1954, pp. 117 to 125; Vol. 594, 1955, pp. 165 to 176, and U.S. Pat. No. 2,671,112) the present process differs on the one hand by the construction scheme

C - ^ - C - - C - C

and on the other hand by the type of dehydration and hydrogenation, which is carried out in one step (see also J. Chem. Soc, London, 1954, pp. 4006 to 4009). The starting materials of the process can, for example can be produced as follows:

Process for the production of
Polyene aldehydes with 19 carbon atoms

Applicant:

F. Hoffmann-La Roche Sd Co.
Aktiengesellschaft, Basel (Switzerland)

Representative: Dr. G. Schmitt, lawyer,
Loerrach (Bad.), Friedrichstr. 3

Claimed priority:
Switzerland from July 20, 19555

Dr. Otto Isler, Dr. Rudolf Rüegg,

Dr. Marc Montavon, Basel,

and Dr. Paul Zeller, Neuallschwil, Basel (Switzerland),
have been named as inventors

cyclohexen- (2 ') - ylidene] -2-methylbutene- (2) -al- (l); For purification, this product is distilled in a Hickmann flask under a high vacuum; Kp. _0j03 9O ⁰ C. A completely

4-i2 ', 6 ^/ , 6'-trimethylcyclohexen- (2') -yIidene] -2-methylbutene- (2) -al- (l) [dehydro- (retro) -C ₁₄ -aldehyde]

30 parts by weight of 4-j2 ', 6', 6'-trimethylcyclohexen- (l ') - yl] -2-methylbutene- (2) -al- (l), dissolved in 210 parts by weight of methylene chloride, are mixed with 13.5 parts by weight of sodium bicarbonate and 9 Parts by weight of calcium oxide cooled to 0 ° C with stirring. Then 28 parts by weight of N-bromosuccinimide are added and the temperature is maintained for 3 hours by occasional cooling to 5 to 10 ^° C. The mixture turns yellow to red after a while and slowly becomes colorless again. It is then filtered, 30 parts by weight of quinoline are added and the methylene chloride is removed in vacuo. A further 30 parts by weight of quinoline are then added and the mixture is heated on the steam bath under nitrogen for 2 hours. Are then added to 350 parts by weight Peiroläiher (Kp. 30 to 6O ⁰ C) and poured while stirring on 250 parts by weight of 3 N sulfuric acid and ice. The insoluble resin is filtered off, the aqueous layer is separated off and the petroleum ether solution is washed once with water, dilute sodium bicarbonate solution and water. After drying the petroleum ether solution over sodium sulfate and evaporation, 29.4 parts by weight of crude 4- [2 ^/ , 6 ^/ , 6'-trimethyl-pure product are obtained if the compound is still distilled through a Vigreux column (30 cm). The aldehyde forms a yellow, thin oil, nf = 1.6152; Ultraviolet absorption maximum at 318 ΐημ; E} _c ° ^ = 1610 (in petroleum ether).

4- [2 ', 6 ^/ , 6'-trimethylcyclohexadien- (l ^/ , 3') - yl] -2-methylbutene- (2) -al- (l) [dehydro - /? - C ₁₄ -aldehyde]

136 parts by weight of 4- ^r 2 ', 6', 6'-trimethylcyclohexen- (2 ') ylidene] -2-methylbutene- (2) -al- (l) are combined with 97 parts by volume of isopropenyl acetate and 0.7 parts by weight of p-toluenesulfonic acid 3 heated up to 4 hours while passing a gentle stream of nitrogen at 100 to 14O ⁰ C, and the liberated acetone continuously distilled off from the reaction mixture. The mixture is then allowed to cool. The crude 4- [2 ', 6', 6'-trimethylcyclohexadien- (1 ', 3') - yl] -2-methyl-1-acetoxybutadiene- (1, 3) obtained is hydrolyzed directly. For this purpose, 650 parts by volume of methyl alcohol, 65 parts by volume of water and 46 parts by weight are added. Sodium bicarbonate and the mixture is refluxed with stirring for 5 to 6 hours. They are then poured into 2000 parts by volume of ice water and made weakly acidic with dilute sulfuric acid. The reaction product is taken up in petroleum ether, the petroleum ether solution is washed with sodium bicarbonate solution and dried over sodium sulfate. After this

709846/488

Distilling off the solvent, the residue is distilled in a high vacuum. 98 parts by weight of 4- [2 ', 6', 6'-trimethylcyclohexadien- (1 ', 3') -yl] -2-methylbutene- (2) -al- (1) are obtained; B.p. ₀ , δ ₅ 80 ⁰ C; n% = 1.530; Ultraviolet absorption maxima at 224 and 268 mp .; Ej *. = 795 and 345 (in petroleum ether solution).

6'6'-Tnmethyl (^ h «yMMi] -2-methylbutene- (2) -al- (l) [Iso-C ₁₄ -aldehyde]

The ethoxyacetylenecarbinol obtained by condensation of ethoxyacetylene with 2,6,6-trimethylcyclohexanone- (l) is partially hydrogenated on the triple bond in a manner known per se, the resulting Ethoxyethylene carbinol hydrolyzed with acid, the 2,6,6-trimethylcyclohexylidene acetaldehyde formed acetalized, the acetal is condensed in the presence of an acidic condensation agent with a propenyl ether and the condensation product obtained is treated with acid.

or dilithium compound is then expediently reacted with methylglyoxal acetal in the same solvent. Lower aliphatic acetals, such as 1,1-dimethoxy or 1,1-diethoxy or 1,1-dibutoxypropanone (2) [methylglyoxaldimethyl or diethyl or dibutyl acetal], or cyclic acetals are suitable for this purpose Acetals, such as l, l-ethylenedihydroxypropanone- (2) [methylglvoxalethylene acetal]. The C ₁₆ acetylene carbinol is preferably treated in a solvent such as diethyl ether with 2 moles of alkyl magnesium halide and the dimagnesium halide compound formed is condensed with 1 mole of methyl glyoxal acetal without isolation and purification. The condensation product is best hydrolyzed in the usual way without purification, for example by

¹ S pouring into a mixture of ice and dilute sulfuric acid, _{the corresponding C 19} dihydroxyaldehyde acetal being obtained _{depending on the C 16} acetylene carbinol and methylglyoxal acetal used. From the ß- or dehydro - /? - or iso- or dehydro- _(ret ro) - C ₁₆ - acetylenecarbinol and methylglyoxalacetal 8- [2 ', 6', 6'-trimethylcyclohexen- (r) - yl] - or 8- [2 ', 6', 6'-trimethylcyclohexadien- (1 ', 3') - yl] - and 8- [2 ', 6', 6'-trimethylcyclohexylidene] - and 8, respectively - [2 ', 6', 6'-Trimethylcyclohexen- (2 ') - ylidene] -2,6-dimethyl-2,5-dihydroxyocten- (6) -yne- (3) -acetal- (l) [im hereinafter referred to as ß- or dehydro - /? - or iso- or dehydro- (retro) -C ₁₉ -dihydroxyaldehyde acetal]. The C ₁₉ -dihydroxyaldehyde acetals are viscous oils that have 2 mol of active hydrogen atoms in the Zerewitinoff determination.

Another embodiment of the first stage of the process according to the invention consists in that one first allows the methylglyoxal acetal to react in liquid ammonia with an alkali or alkaline earth acetylide and the condensation product formed, preferably

2-oxopropionaldehyde acetals [methylglyoxal acetals]

These acetals can be obtained from methylglyoxal by

warm with alcohols or glycols in inert solvents in the presence of an acidic condensing agent with constant distillation of the water formed getting produced.

In the first stage of the process according to the invention

ß- or dehydro- / ß- or iso- or dehydro- (retro) -C ₁₄ -aldehyde are allowed to react in a known manner in liquid ammonia with an alkali metal or alkaline earth metal acetylide and the reaction product formed is condensed, preferably after hydrolysis , for 6- [2 ', 6', 6'-trimethylcyclohexen- (l ^/ ) -yl] or 6- [2 ', 6', 6'-trimethylcyclohexadiene- (l ', 3 ^/ ) - yl] - or ö-ß ^ o ^ ö'-trimethylcyclohexylidene] - or 6- [2 ', 6', 6'-trimethylcyclohexen- (2 ') ylidene] -

4-methylhexen- (4) -in ~ (l) -ol- (3) [in the following with ß- or 35 after hydrolysis to 2-methyl-2-hydroxybutin- (3) -ace-dehydro - /? - or iso- or dehydro- (retro) -C ₁₀ -acetylenetal ~ (l), by means of an organometallic reaction with

carbinol], in a known manner by means of an organometallic reaction with a methylglyoxal acetal. The condensation in liquid ammonia can be done under elevated pressure at room temperature or Carry out under normal pressure at the boiling point of ammonia. One condenses with an alkali acetylide, such as sodium or lithium acetylide, or with an alkaline earth acetylide such as calcium acetylide, which one

expediently treated in the same 45 excess lithium aluminum hydride before the condensation reaction. In the vessel and in the same ammonia that is used to condense this reaction, the triple bond is partially hydrogenated, made of alkali or alkaline earth metal and and at the same time, surprisingly, the hydroacetylene can be produced. Preference is given to using xyl groups with the formation of a new double bond for the condensation of lithium acetylide. The C _i4 aldehyde can be split off. According to the invention, partial hydrogenation and cleavage of the hydroxyl groups are advantageously carried out in an inert solvent such as diethyl ether

simultaneously by treating the C ₁₉ -dihydroxyaldehyde acetal in an inert solvent with excess lithium aluminum hydride at room temperature or at an elevated temperature. Suitable solvents are

Acetylene carbinols are colorless to yellowish, distillable 55 aliphatic or cyclic ethers, such as diethyl ether,

Oils that contain ethylene glycol dimethyl ether or dioxane, which is characteristic in the ultraviolet spectrum, or organic,

tertiary amines such as Ν, Ν-diethylaniline or N-ethylmorpholine. In the preferred embodiment, the C ₁₉ -dihydroxyaldehyde acetal is stirred in N, N-diethyl

determination in the cold 1 mole and in the heat 2 moles 6o aniline with 2 to 4 moles of lithium aluminum hydride at 60 to active hydrogen atoms. The condensation of 120 ° C in a nitrogen atmosphere. One obtains from the

C ₁₆ acetylene carbinols with methyl glyoxal acetal take place through an organometallic reaction. One lets ζ. B. act on the C ₁₆ acetylene carbinol in an inert solvent mol alkyl magnesium halide or 2 mol lithium phenyl. The first mole of the organometallic

() g

a C ₁₄ aldehyde, which also gives rise to the above-mentioned C ₁₉ -I) ihydroxyaldehyde acetals. The 2-methyl-2-hydroxybutine- (3) -acetale- (l) are colorless, distillable oils. They show the determination of Zerewitinoff in the cold. 1 mole and 2 moles of active hydrogen atoms when heated.

In the second stage of the process, the C ₁₉ -dihydroxyaldehyde acetals are used in a known manner

be added. The hydrolysis of the condensation product succeeds, for. B. in liquid ammonia by adding an ammonium salt or after removal of the ammonia by treatment with acid. The C ₁₆ -

have absorption maxima (with the exception of / JC ₁₆ -acetylene carbinol, which does not have an absorption maximum above 225 ταμ ). At the Zerewitinoff-

Compound is bound by the hydroxyl group while the second mole with the acetylene bond reacts and the terminal carbon atom condenses

ß- or dehydro - ^ - or iso- or dehydro- (retro) -C ₁₉ -dihydroxyaldehyde acetal the 8- [2 ', 6', 6'-trimethylcyclohexen- (l ') - yl] - or S- ^'.o'.o'-trimethylcyclohexadien- (r, 3 ') - yll- or 8- [2', 6 ', 6'-trimethylcyclohexylidene] - or 8- [2', 6 ', 6'-trimethylcyclohexane - (2 ') - ylidene] -2,6-dimethyloctatriene- (2,4,6) -acetal- (l) [in the following with ß- or dehydro - /? - or. Iso or Referred to as dehydro (retro) -C ₁₉ acetal]. These are viscous oils that in the ultraviolet

] g

makes it possible to sation. The dimagnesium halide 70 formed have absorption maxima which are characteristic of the spectrum.

5 6

In the last stage of the process, the [prepared by heating 1 mole of methyl-

C ₁₉ acetals hydrolyzed in acidic solution, the glyoxal with 1.2 mol of ethylene glycol and 0.001 mol of p-toluene

corresponding C ₁₉ aldehydes are obtained. This sulfonic acid in benzene solution with constant distillation

takes place in a manner known per se, for. B. by stirring the water formed, shaking out the obtained

the C ₁₉ acetals in the presence of water in a 5 benzene solution with dilute sodium bicarbonate solution,

Water-miscible solvent at room temperature. Evaporation of the solvent and vacuum distillation

or at elevated temperature with a mineral acid _{, such as (bp. 10} 102 ° C; nff = 1.4145)] in 50 parts by volume absolute

Sulfuric acid, or with an organic acid such as ether, and heat the mixture for 5 to 7 hours

Acetic acid or p-toluenesulfonic acid. Appropriate are the reflux. The reaction mixture is then

the C ₁₉ acetals with a 90 ° / ₀ acetic acid short time io to a mixture of 130 parts by volume of 3N sulfuric acid

95 ° C heated or poured in alcoholic solution with poured and 200 parts by weight of ice. The ether layer

dilute sulfuric acid for a few hours at room temperature is separated, with water and with 5% sodium

temperature stirred. bicarbonate solution washed with sodium sulfate

The obtained by the present process is dried and evaporated. 35.5 parts by weight are obtained

C ₁₉ aldehydes have characteristic absorption 15 oily 8- [2 ', 6', 6'-trimethylcyclohexen- (l ') - yl] -2,6-di-

maxima in the ultraviolet spectrum. As a result of the cis-trans-methyl-2,5-dihydroxyocten- (6) -in- (3) -ethylene acetal- (l),

There are different isomerism at the double bonds, which can be achieved by distributing between solvents and chromium.

Three-dimensional shapes of these aldehydes. Losses can be cleaned up by zer- matography. The Zerewitinoffbe-

To avoid sedimentation, it is recommended that during the mood shows 2 moles of active hydrogen atoms.
whole process to work in an inert atmosphere. 20th

The products of the process are valuable intermediate profiles
products for the synthesis of ^ -carotene and carotenoids, ^c ) ^ -aldehyde-ethylene acetal
like bisdehydrocarotene. So they can by a 5.2 parts by weight of the organometallic reaction obtained in accordance with paragraph b) on both sides of acetylene anla- product are in 140 parts by volume N, N-diethylaniline like, the C ₄₀ diol formed can be dissolved by treatment 25, whereupon the Dehydrate solution at 5 to 10 ⁰ C with stirring with dehydrating agents and the gradually a solution of 1.7 parts by weight of lithium formed product by partial hydrogenation of the tri-aluminum hydride in 45 parts by volume of absolute ether and subsequent isomerization in carotene added and the mixture for 20 hours 75 ⁰ C heated oide transfer. That way you can get out of it. The reaction mixture is then converted to a mixture / JC ₁₉ -aldehyde / S-carotene, from the dehydro- / 3-C ₁₉ -al- 30 of 250 parts by volume of 3N sulfuric acid and 200 parts by weight of the bisdehydrocarotene, from the IsO-C ₁₉ - Aldehyde share poured ice and the / 3-carotene and extracted from the dehydro- (retro) -C ₁₉ -aldehyde with 100 parts by volume of petroleum ether. The petroleum ether solution will win successively with the bisdehydrocarotene. All these carotenoids of ice-cold 3N sulfuric acid, with water and with both, can be used as fat coloring agents. diluted sodium bicarbonate solution, washed with Na-

35 dried trium sulfate and evaporated. You get

Bpisniel 1 4.9 parts by weight of crude S- ^ ö'.o'-trimethylcyclohexen-

Rr A IH ha ^ ' ^yl J ~ ² ' ⁶ ' dimethyloctatriene- (2,4,6) -ethylene acetal- (1),

pC ₁₉ -aldehyde ^ ₈ "by partitioning between solvents and

a) / S-C ^ -acetylene carbinol can be purified by chromatography; yellowish oil

One passes into a solution of 1 part by weight of lithium 4 ° with ultraviolet absorption maxima at 278 and 289 πιμ

400 parts of liquid ammonia dry acetone in petroleum ether.

free acetylene until the lithium is completely converted ,, _{Q n} ,,,, ·,

• μ t \ -uj. j. 1 -χι. Π ·· !. ■ ι τι. d) TLC ₁ o-aldehyde

is. Then, with vigorous stirring, give within ^r

15 minutes a solution of 25 parts by weight 5 parts by weight 8- ^ 6 ^ 6'-trimethylcyclohexen- (r) -yl-

4- [2 ', 6 ^/ , 6'-trimethylcyclohexen- (l') - yl] -2-methylbutene- +5 2,6-dimethyloctatriene- (2,4,6) -ethylene acetal- (1) are (2 ) -al- (l) in 100 parts by volume dry ether and dissolved in 90 parts by volume glacial acetic acid. The reaction mixture obtained is stirred with moisture dissolving 10 parts by volume of water and 10 parts by weight of water intensively for 20 hours. Small trium acetate is then added and the mixture is heated in portions 16 parts by weight of ammonium chloride for 2 hours and a nitrogen atmosphere to 95 ° C. The reaction solution is allowed to evaporate the ammonia. After the addition of 50 it is then cooled, diluted with 200 parts by volume of water, 120 parts by volume of water and 100 parts by volume of ether and extracted with 100 parts by volume of petroleum ether. The petroleum ether layer is separated off, washed with water, dried with ethereal solution with water and with dilute sodium sodium sulfate and concentrated. The residue is washed with trium bicarbonate solution and distilled with sodium sulfate in a high vacuum. It is dried and evaporated on this. The residue crystallizes in the manner of 27.5 parts by weight of o - ^ '. O' ^ '- trimethylcyclohexene-55 from petroleum ether or methanol and gives 8- [2', 6 ', 6'-tri- (1') -yl] -4 -methylhexen- (4) -in- (1) -oil- (3); B.p. _{0) 02} 100 ⁰ C; methylcyclohexen- (1 ') -yl] -2,6-dimethyloctatriene- (2,4,6) - n ² p = 1.510. ' ^a l- (l) ^from F- 62 to 63 ° C; Ultraviolet absorption maxima

at 311 to 313 and 323 to 325 ΐημ in petroleum ether. That Phenylsemicarbazone forms yellow needles from methylene

b) ß-C ^ -dihydroxyaldehydäthylenacetal _6o chloride — methanol; M.p. 204-206 ° C; Ultraviolet

23.2 parts by weight of o-P'.ö'.o'-trimethylcyclo- sorption maxima at 332 and 347 μm are dissolved in petroleum ether. Aushexen- (l ') - yl] -4-methylhexen- (4) -in- (l) -ol- (3) inl00 Space loot: 2.8 parts by weight,
share absolute ether and issue the solution one

5.4 parts by weight of magnesium and 26 parts by weight of Example 2

Ethyl bromide in 100 parts by volume of absolute ether

made ethylmagnesium bromide solution with stirring at P 19 Y

10 to 15 ⁰ C gradually increases. The ^a ) 2-methyl-2-hydroxybutyn- (3) -al- (l) -dibutyl acetal is then heated

The mixture is refluxed for 1 hour, then it is cooled with Man passes into a solution of 7.2 parts by weight

Ice-water, with stirring at about 20 ⁰ C lithium in 600 parts by volume of liquid ammonia dry, solution of 12 parts by weight Methylglyoxaläthylenacetal 7 ° acetone-free acetylene, until the lithium completely

is implemented. Then a solution of 121 parts by weight of 1,1-dibutoxypropanone- (2) in 300 parts by volume of absolute ether is added with stirring over the course of 10 minutes and the mixture is shaken in the autoclave for 20 hours at room temperature. 114 parts by weight of ammonium chloride are then slowly added to the reaction mixture and the ammonia is allowed to evaporate. 1000 parts by volume of dry ether are then added, the lithium chloride and excess ammonium chloride are nitrated, the ether is evaporated and the residue is fractionated in vacuo. 105 parts by weight of 2-methyl-2-hydroxybutyne - (3) - al - (1) - dibutyl acetal are obtained; Bp. ₁₆ 130 to 135 ⁰ C. The Zerewitinoff determination shows 1 mol of active hydrogen atoms in the cold and 2 mol of active hydrogen atoms in the heat.

b) / 3-C ₁ g-dihydroxyaldehyde dibutyl acetal

23 parts by weight of 2-methyl-2-hydroxybutyn- (3) -al- (l) -dibutyl acetal are dissolved in 50 parts by volume of absolute ether and the solution is gradually added at 10 to 15 ° C. with stirring to one of 5.4 parts by weight of magnesium and Grignard solution prepared 26 parts by weight of ethyl bromide in 100 parts by volume of absolute ether. The mixture is then refluxed for 60 minutes, cooled with ice water, a solution of 20 ^{parts by weight of 4- [2 ', 6', 6 /} -trimethylcyclohexen- (l ') - yl] - is added at 15 to 20 ° C. Gradually add 2-methylbutene- (2) -al- (l) in 100 parts by volume of absolute ether and heat the mixture under reflux for 6 to 8 hours. The reaction mixture is then worked up as indicated in Example 1, b). In this way, 43 parts by weight of oily 8 - [2 ', 6', 6 '-trimethylcyclohexene - (Γ) -yl] -2,6-dimethyl-2,5-dihydroxyocten- (6) -in- (3) -dibutyl acetal- (l) which can be purified by partitioning between solvents and chromatography. The Zerewitinoff determination shows 2 mol of active hydrogen atoms.

c) JO-C ₁₉ aldehyde dibutyl acetal

6 parts by weight of S - ^ '. O'.o'-trimethylcyclohexen- (Γ) -yl] ~ 2,6-dimethyl-2,5-dihydroxyocten- (6) -in- (3) -dibutyl acetal- (l ) in 140 parts by volume of dry ether, slowly adding a solution of 2 parts by weight of lithium aluminum hydride in 50 parts by volume of absolute ether to the solution at 5 to 10 ° C. with stirring and heating the mixture under reflux for 50 hours. The reaction mixture is then worked up as indicated in Example 1, c). In this way, the crude 8- [2 ', 6', 6'-trimethylcyclohexen - (V) - yl] - 2,6 - dimethyl octatrien- (2,4,6) -dibutyl acetal- (l), which is obtained by Chromatography can be purified. Ultraviolet absorption maxima at 278 and 289 ηαμ in petroleum ether. Yield: 5.2 parts by weight.

d) β-C ^ aldehyde

5.5 parts by weight of 8- [2 ', 6', 6'-trimethylcyclohexen - (Γ) - yl] -2,6 - dimethyloctatriene - (2,4,6) - dibutyl acetal- ^) are dissolved in 100 parts by volume of ethyl alcohol, gives the solution 5 parts by volume of 3N sulfuric acid and leaves the Stand mixture for 20 hours in a nitrogen atmosphere at room temperature. The reaction mixture is then diluted with 200 parts by volume of water and extracted with it Petroleum ether, the petroleum ether solution washes with dilute sodium bicarbonate solution, dried over sodium sulfate and evaporates the petroleum ether. This is obtained by crystallization in petroleum ether or methanol 8 - [2 ', 6', O '- trimethylcyclohexene - (!') - yl] - 2,6 - dimethyloctatriene- (2,4,6) -al- (l) as yellowish crystals with a melting point of 62 to 63 ° C. Yield: 3 parts by weight.

Example 3
Dehydro-ß-Q ₉ -aldehyde

a) Dehydro-jS-Cj g-acetylenecarbinol

By condensing 27.8 parts by weight of 4- [2 ', 6', o'-triniethylcyclohexadien- (1 ', 3') -yl] -2-methylbutene- (2) -al- (l) with lithium acetylide and working up the Reaction product in the manner described in Example 1, a) gives the o- ^ o'.o'-trimethylcyclohexadien- (l ^/ , 3 ') - yl] -4-methylhexen- (4) -in- (l) - ol- (3) as "yellowish oil of bp. _0i04 HO ⁰ C; n% = 1.528; ultraviolet absorption maximum at 266 ηιμ in petroleum ether.

b) Dehydro- / 3-C ₁₉ -dihydroxyaldehydethylene acetal

By condensation of 11.5 parts by weight 6- [2 ', 6', 6 '- trimethylcyclohexadien - (Γ, 3') - yl] - 4 - methylhexen- (4) -in- (l) -ol- (3) with Methylglyoxaläthylenacetal and work-up of the reaction product in the example 1, b) described manner one obtains the 8- [2 ', 6', 6'-trimethyl-

ao cyclohexadien - (l ', 3') - yl] -2,6 - dimethyl -2,5 - dihydroxyocten- (6) -in- (3) - ethylene acetal (l) as a yellowish oil. Ultraviolet absorption maximum at 266 πιμ in petroleum ether. Yield: 17 parts by weight.

c) DeIiVdTO-JO-C ₁₉ -aldehydethylene acetal

By treating 17 parts by weight of 8- [2 ', 6', 6'-trimethylcyclohexadien - (Γ, 3 ') - yl] - 2,6 - dimethyl - 2,5 - dihydroxyocten- (6) -yne- (3) -äthylenacetal- (l) with lithium aluminum hydride and working up the reaction product in the manner described in Example 1, c) gives the 8- [2 ^/ , 6 ', 6 ^/ -Trimethylcyclohexadien- (1 ^/ , 3') - yl] - 2,6-dimethyloctatrien- (2,4,6) -äthylenacetal- (l) with an ultraviolet absorption maximum at 281 ηιμ in petroleum ether. Yield: 14.4 parts by weight.

d) Dehydro - ^ - Cjg-aldehyde

Saponified is S- ^ o'.o'-Trimethylcyclohexadien-ir ^ ') - yl] -2,6-dimethyloctatrien- (2,4,6) -äthylenacetal- (l) in the example 1, d) indicated W ^r else, one obtains 8 - [2 ', 6', 6 '- Trimethylcyclohexadien - (l', 3 ') - yl] - 2,6 - dimethyloctatrien- (2,4,6) -AL- (l) . From petroleum ether it forms yellowish crystals with a temperature of 64 to 66 ^C C; Ultraviolet absorption maximum at 315 ΐημ in petroleum ether. Phenyl semicarbazone, mp 197-200 ° C; Ultra violet absorption maxima at 333 and 348 ma in petroleum ether. Ausheute: about 60 ° / ₀ of the theory.

Example 4

Iso-C ₁₉ aldehyde

a) Iso-Qg-dihydroxyaldehyde dibutyl acetal

By condensation of 2.85 parts by weight of 4- [2 ', 6', o'-trimethylcyclohexylidene ^ -methylbutene- ^ l-al-II) with 3.3 parts by weight of 2-methyl-2-hydroxybutyn- (3) -al- (l) -dibutyl acetal in the manner described in Example 2, b) the 8-r2 ^ 6 ^ 6'-trimethylcyclohexylidene] -2,6-dimethyl-2,5 is obtained - dihydroxyoctene - (6) - yne - (3) - dibutyl acetal - (1). Ultraviolet absorption maximum at 250 ηιμ in petroleum ether. Yield: about 6 parts by weight.

b) Iso-Cuj-aldehyde dibutyl acetal

By treating 5.1 parts by weight of 8- [2 ', 6', 6'-methylcyclohexylidene] - 2,6 - dimethyl - 2,5 - dihydroxyocten- (6) -in- (3) -dibutyl acetal- (1) with 1.7 parts by weight of lithium aluminum hydride in the manner described in Example 1, c) gives the 8- [2 ', 6', 6'-trimethylcyclohexylidene] - 2,6 - dimethyloctatriene - (2,4,6) - dibutyl acetal ( I) with absorption maxima in the LHtraviolet spectrum at 307, 321 and 338 τημ in petroleum ether. Yield: 2.5 parts by weight.

J-5

c) IsO-C ₁₉ aldehyde

Saponified one 8- [2 ^ 6 ^ 6'-trimethylcyclohexylidene] -2,6-dimethyloctatrien- (2,4,6) -dibutylacetal- (l) after the compound described in Example 1, d) method, we obtain 8 - [2 ', 6', 6 '- trimethylcyclohexylidene] -2,6-dimethyloctatriene- (2,4,6) -al- (l) as a yellowish oil; Ultraviolet absorption maxima at 334, 356 and 367 πιμ in petroleum ether. The phenylsemicarbazone forms yellow needles from methylene chloride · - methanol with a melting point of 201 to 203 ° C; Ultraviolet absorption maxima at 352, 369 and 391 πιμ in petroleum ether. Yield: 60 ° / ₀ of theory.

Example 5

Dehydro (retro) -C ₁₉ aldehyde
a) Dehydro- (retro) -C ₁₆ -acetylenecarbinol

By condensing 12.5 parts by weight of 4 ~ \ 2 ', 6', 6 '- trimethylcyclohexen - (2') - ylidene] -2 - methylbutene - (2) al- (l) with lithium acetylide and working up the reaction product in the example 1, a), the 6- [2 ', 6', 6'-trimethylcyclohexen- (2 ') - ylidene] -4-methylhexen- (4) -in- (l) -ol- (3) is obtained as a yellow oil with a _{boiling point of 0.15} 109 ⁰ C; η | ³ = 1.572; Ultraviolet absorption maximum at 285.5 ιημ in petroleum ether. Yield: 13 parts by weight.

b) Dehydro (retro) C ₁₉ dihydroxyaldehyde ethylene acetal

By condensation of 11.7 parts by weight 6- [2 ', 6', 6'-trimethylcyclohexen- (2 ') -ylidene] -4-methylhexen- (4) -in- (1) -ol- (3) with Methylglyoxaläthylenacetal and work-up of the reaction product in the example 1, b) described manner one obtains the S-p'.o'.o'-trimethylcyclohexene - (2 ') - ylidene] - 2,6 - dimethyl - 2,5 - dihydroxyocten- (6) -in- (3) -ethylene acetal- (l) as a yellowish oil. Ultraviolet absorption maximum at 285.5 ηιμ in petroleum ether. Yield: 17.3 parts by weight.

c) Dehydro- (retro) -C ₁₉ -aldehydethylene acetal

By treating 17 parts by weight of 8- [2 ', 6', 6'-TrI-methylcyclohexen- (2 ') - ylidene] - 2,6 - dimethyl - 2,5 - dihydroxyocten- (6) -yne- (3) -ethylene acetal- (1) with lithium aluminum hydride and work-up of the reaction product in the manner described in Example 1, c) gives the 8 - [2 ', 6', 6 '- trimethylcyclohexen - (2') - ylidene] - 2,6 - dimethyloctatrien- (2,4,6) ~ ethylene acetal- (l) with ultraviolet absorption maxima at 347 and 365 ιημ in petroleum ether. Yield: 6.5 parts by weight.

2,6-dimethyloctatriene- (2,4,6) -al- (l) as a yellow oil with ultraviolet absorption maxima at 383 and 403 ηαμ in petroleum ether. The phenylsemicarbazone forms yellow crystals from methylene chloride - methanol with a melting point of 198 to 201 ^° C .; Ultra violet absorption maxima at 373, 393 and 417 πιμ in petroleum ether. Yield: about 60% of theory.

For the preparation of the starting compounds, protection is not given in the context of the present invention claimed.

Claims (2)

Patent claims: 1. A process for the preparation of polyenaldehydes having 19 carbon atoms, characterized in that acetylene is converted in a known manner by an organometallic reaction on the one hand with a methylglyoxal _{acetal and on the other hand with a C 11} aldehyde of the general formula R-CH = C-CHO CH ₃ R eitlen means hydrocarbon radical with the carbon skeleton of cyclogeraniol, condensed, the condensation product formed is treated in a known manner with excess lithium aluminum hydride and the C ₁₉ acetal obtained is then hydrolyzed in the usual way in an acidic solution. 2. The method according to claim 1, characterized in that first lithium acetylide in liquid ammonia with 4- [2 ', 6', 6'-trimethylcyclohexen- (l ') - yl] - or 4-L2', 6 ', 6'-Trimethylcyclohexadien- (l ', 3') - yl] - or 4 - ["2 ', 6', 6'-Trimethylcyclohexyliden] - or 4- [2 ' ₎ 6', 6'-Trimethylcyclohexen- (2 ') - ylidene] -2-methylbutene- (2) ~ al- (l) condenses, the lithium compound formed is hydrolyzed, the acetylene carbinol obtained is condensed by means of a Grignard reaction with methylglyoxalacetal, the condensation product formed in diethylaniline with excess lithium aluminum hydride is heated and the resulting Acetal of 8- [2 ', 6', 6'-trimethylcyclohexen- (l ') - yl] - or S - ^'. O'.o'-trimethylcyclohexadien- (l ', 3') - yl] - or 8- [2 ', 6', 6'-trimethylcyclohexylidene] - or 8- [2 ', 6', 6'-trimeth3'lcyclohexen- (2 ') - ylidene] -2,6-dimethyl-octatriene - (2,4,6) -al- (l) hydrolyzed with glacial acetic acid and sodium acetate or sulfuric acid. d) dehydro- (retro) -C ₁₉ -aldehyde If the 8- [2 ', 6', 6'-Trimethylcyclohexen- (2 ') - ylidene] - 2,6-dimethyloctatrien- (2,4,6) -äthylenacetal- (1) is saponified according to the example 1, d) described method, one obtains 8-f2 ', 6 ^/ , 6'-trimethylcyclohexen- (2') - ylidene] - publications considered:
German Patent No. 855 399;
U.S. Patent No. 2,671,112;
Dear. Ann. d. Chem., Vol. 570, 1950, pp. 54 to 72; Vol. 588, 1954, pp. 117 to 125; Vol. 594, 1955, pp. 165 to 176;
J. Chem. Soc, 1954, pp. 4006 to 4009. © 709 84.5 / 488 12.