Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C11/00—Aliphatic unsaturated hydrocarbons
  • C07C11/28—Aliphatic unsaturated hydrocarbons containing carbon-to-carbon double bonds and carbon-to-carbon triple bonds
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C1/00—Preparation of hydrocarbons from one or more compounds, none of them being a hydrocarbon
  • C07C1/20—Preparation of hydrocarbons from one or more compounds, none of them being a hydrocarbon starting from organic compounds containing only oxygen atoms as heteroatoms
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S585/00—Chemistry of hydrocarbon compounds
  • Y10S585/929—Special chemical considerations
  • Y10S585/93—Process including synthesis of nonhydrocarbon intermediate
  • Y10S585/934—Chalcogen-containing

Definitions

• the invention concerns a process for the manufacture of a multiple unsaturated aliphatic compound of the formula:
• CH3 HCECCH (
• a process has been found now for the manufacture of multiple unsaturated, aliphatic compounds, by conversion of a hydroxyl group of them into a grouping that can be split off, while forming a double bond, followed by the introduction of the double bond, characterized in that a compound of the general formula 3,401,210 Patented Sept. 10, 1968 in which R represents an alkyl group whether or not branched with one to six carbon atoms, possibly substituted, is converted into an ether, treating it subsequently with an alkali metal amide in liquid ammonia, or a lower aliphatic amine.
• ethers used as intermediate products can be converted in the alkali medium according to the invention, as it has been known that ,B-acetylene ethers are stable in alkaline medium, as goes forward, for instance, from the synthesis of l-methoxy-but-3-yne from acetylene sodium and l-methoxy-Z- bromoethane in liquid ammonia, as described in J. Am. Chem. Soc., 59, 213 (1937). With the present method yields can be obtained of, for instance, 70%.
• the present final products are important intermediates for the synthesis of compounds of the vitamin A series.
• 1-alkoXy-3-methyl-hexa-1,3-dien- S-yne with fl-ionone compounds can be obtained directly of the carbon skeleton of vitamin A, as described in the published Netherlands patent application 6,404,175.
• These final products are also of importance for the synthesis of carotenes and carotenoids.
• the ethers functioning as intermediates in the method of preparation according to the invention, may be prepared in a conventional manner. Preferably they are prepared by the addition of the alcohol to a vinylether of the general formula:
• R R and R represent hydrogen or an alkyl group with 1-6 carbon atoms and R; an alkyl group with 1-6 carbon atoms.
• the splitting off of the ether group, while forming a double bond, is performed with an alkali metal amide, such as lithium, sodium and potassium amide, in liquid ammonia or a lower amine, such as methyl, ethyl and triethyl amine, which solvents may be diluted, if desired, with, for instance, benzene, toluene, dimethylformamide, dimethylacetamide and tetrahydrofuran.
• the amide may be added either to the ammonia or may be formed in it by dissolving the required amount of alkali metal in the presence of a small amount of ferrinitrate as catalyst.
• the temperature at which the splitting off of the ether group occurs depends on the strength of the base used. When potassium amide is used, this reaction proceeds satisfactorily at a temperature of 30 C. to -65 C.
• the metal compound formed in this reaction is decomposed with, for instance, ammonium chloride or a dilute mineral acid.
• the final product may be isolated from the reaction mixture by extraction with a solvent, for instance, ether. After drying the extract and removing the solvent the final product may be purified by fractionated distillation at reduced pressure.
• the refraction indices observed of the mixture of isomers of l-methoxy-hexadienyne are between 1.52 and 1.56, dependent on the ratio of cis-trans. By means of gaschromatography they may be separated, if desired. Both isomers can be used in the synthesis of vitamin A.
• R represents a methyl, ethyl, propyl, isopropyl and butyl group, which may be substituted by a hydroxyl group, an acyloxy group, an alkoxy group or by an amino group.
• the ethers used as intermediates may be derived from, for instance, an aliphatic alcohol, such as methanol, ethanol, propanol and t-butanol from aromatic hydroxyl compounds, such as phenol, p-nitrophenol, p-chlorophenol and p-methoxyphenol, as well as from heterocyclic compounds, such as dihydropyran.
• an aliphatic alcohol such as methanol, ethanol, propanol and t-butanol
• aromatic hydroxyl compounds such as phenol, p-nitrophenol, p-chlorophenol and p-methoxyphenol
• heterocyclic compounds such as dihydropyran.
• vinylethers examples include methoxy-ethene, ethoxyethene, butoxy and isobutoxyethene and further the compounds of the following formulae:
• the preparation of the relative alkynyl ethers by means of these vinylethers takes place according to one of the common methods, for instance, by means of an acid, such as p-toluene sulphonic acid, dinitrobenzene sulphonic acid or anhydrous hydrochloric acid, or by means of a Lewis acid, such as borotrifiuoride-etherate.
• the reaction may occur in a medium free from solvent or in an indifferent solvent, such as benzene, petroleumether, chloroform, carbontetrachlolide, dialkylether, for instance, ethoxyethane, and in tetrahydrofuran or in a mixture of two or more of these solvents.
• the formation of the ether occurs at temperature between 30 C. and 100 C., preferably at room temperature.
• the alkynylethers formed in this reaction may contain one or two asymmetric carbon atoms, one of which may be present in the ether group to be split off.
• the reaction mixture obtained may therefore be a mixture of hardly separable disastereoisomers, which, as a mixture, are further converted.
• Example 1 (A) To 61.13 gm. of 1,1-dimethoxy-3-hydroxy-3- methyl-hex-S-yne 68.78 gm. of ethyl-vinylether were added and, while stirring, 0.035 gm. of p toluene sulphonic acid. The temperature rose in a short time to 5 3 C. and fell slowly afterwards. After 1 hours stirring the reaction mixture was poured out into a saturated sodium chloride solution to which a small amount of potassium carbonate was added. The organic layer formed was separated from the water layer. The latter was extracted a few times with ether. The joint organic layers were next washed to neutral with a saturated sodium chloride solution.
• Example 1 In the way of Example 1, starting from 1,1-diethoxy-3- hydroxy-3-methyl-hex-5-yne and dihydropyran, by means ofa little p-toluene sulphonic acid as catalyst, the 3-tetrahydropyranylether was prepared. After isolation and distillation, it was converted at -50 C. into 1-ethoxy-3- methyl-hexa-1,3-dien-5-yne with sodium amide in liquid ammonia, in which process 10 mol of sodium amide per mol of ether were used.
• Example 3 In 800 ml. of liquid ammonia the sodium amide was made from 0.1 mol of sodium and a trace of ferric nitrate. After cooling to C. to 0.1 mol of 3-hydroxy-3-methyl-hex-5-yne, boiling point 48 C. at 13 mm. Hg, dissolved in 60 ml. of tetrahydrofuran was added to it. Next were added 6.5 ml. of methyliodide. After 3 hours stirring at 75 C. the ammonia was evaporated and water was added gently. The water layer was next extracted with ether. The organic layers obtained were washed till neutral reaction. After drying on sodium sulphate the extract was filtered and the solvent evaporated in vacuo. Finally the residue was distilled in vacuo to obtain crude 3-methoxy-3-methyl-hex-5-yne.
• Example 4 In an analogous manner as described in Example 3 from 5-hydroxy-5-methyl-oct-7-yn the S-pyranylether was prepared and after isolation with KNH in liquid ammonia converted into the 5-methyl-octa-5-en-7-yne in a yield of 56 What is claimed is:
• R represents an alkyl group having 1-6- carbon atoms, which may be branched and substituted, comprising etherifying the hydroxyl group of a compound of the formula:
• R represents an alkyl group with 1-6 carbon atoms
• R3-CC-Ru in which R R and R represent a member of the group consisting of hydrogen and an alkyl group with 1-6 carbon atoms and R an alkyl group with 1-6 carbon atoms.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=19794400

Family Applications (1)

Country Status (5)

Cited By (3)

Citations (3)

• 1965
  • 1965-10-18 NL NL6513473A patent/NL6513473A/xx unknown
• 1966
  • 1966-10-03 US US583983A patent/US3401210A/en not_active Expired - Lifetime
  • 1966-10-11 DE DE19661593179 patent/DE1593179A1/de active Pending
  • 1966-10-14 GB GB45992/66A patent/GB1165204A/en not_active Expired
  • 1966-10-18 BE BE688402D patent/BE688402A/xx unknown

Patent Citations (3)

Also Published As

Similar Documents