Showing papers on "Methyl vinyl ketone published in 1976"
TL;DR: In this paper, a reaction sequence of trimethyl-hydroquinone with methyl vinyl ketone in acidic methanol gave rac.-2methoxy-2,5,7,8,8-tetramethyl-chroman-6-ol (8), which was converted to (2R, 4′R, 8′R)-α-tocopherol (1d) using a side chain derived from phytol.
Abstract: Reaction of trimethyl-hydroquinone with methyl vinyl ketone in acidic methanol gave rac.-2-methoxy-2,5,7,8-tetramethyl-chroman-6-ol (8). This acetal was converted in four steps to rac.-(6-hydroxy-2,5,7,8-tetramethyl-chroman-2-yl)acetic acid (13). Acid 13 was readily resolved with α-methyl-benzylamine to give the (S)-enantiomer 14. Treatment of the unwanted (2 R)-isomer with acid regenerated 13, thus leading to an efficient use of this compound. Employing a side chain derived from phytol, 14 was converted to (2R, 4′R, 8′R)-α-tocopherol (1d, ‘natural’ vitamin E). A reaction sequence from 14 involving two highly stereoselective Claisen rearrangements has provided the first total synthesis of (2R,'E,7′E)-α-tocotrienol (2d).
75 citations
46 citations
TL;DR: The synthesis of the entitled four alkaloids, which were oxindole alkaloid of Uncaria species and Mitragyna species, has been completed through several steps starting from the condensation of 2-hydroxytryptamine hydrochloride with 3, 3-dimethoxy-propionaldehyde (V) as mentioned in this paper.
Abstract: The total synthesis of the entitled four alkaloids, which were oxindole alkaloids of Uncaria species and Mitragyna species, has been completed through several steps starting from the condensation of 2-hydroxytryptamine hydrochloride (IV) with 3, 3-dimethoxy-propionaldehyde (V). The condensation product (XV) was submitted to the Michael addition with methyl vinyl ketone, followed by acid treatment to give the α, β-unsaturated ketones (XIVa, b) as two stereoisomers. The isomer (XIVb) was condensed with methyl malonate to yield the ester (XXb), which was hydrogenated with Adams' catalyst to XXIb. The compound (XXIb) was treated with dil. sulfuric acid to give the lactones (XXIIa, b) as two spiro-iso-mers, the isomer (XXIIa) of which in turn, was heated with the aminal ester, then stirred with 5% MeOH-HCl, refluxed with aq. dioxane and heated with PPA to afford (±)-for-mosanine (IIIa) and (±)-isoformosanine (IIIb). Similarly, the lactone (XXVa) which was obtained from (XXb) by reduction with NaBH4 and hydrolysis with acid, gave (±)-mitraphylline (IIa) and (±)-isomitraphylline (IIb).
30 citations
TL;DR: In this article, a two-step synthesis of 3,4-dimethylpyrrole via the reduction of 3-carboethoxy-4-methyl-Pyrrole is described.
16 citations
TL;DR: In this article, the effect of substitution in the α-and β-position in the cycloalkanone, its ringsize, and the structure of the Michael acceptor (alkyl vinyl ketone) was illustrated in reactions of the enamines of 2,5-dimethylcyclohexanone 22, carvomenthone 19, menthone 26, dihydrocarvone 28 and tetrahydroeucarvone 32 with methyl-and/or ethyl Vinyl ketone.
13 citations
TL;DR: In this paper, eleven structurally different α, β-unsaturated ketones were subjected to the Clemmensen reduction under anhydrous conditions using amalgamated zinc, hydrogen chloride in a solution of ethyl ether, and acetic anhydride.
Abstract: Eleven structurally different α, β-unsaturated ketones were subjected to the Clemmensen reduction under anhydrous conditions using amalgamated zinc, hydrogen chloride in a solution of ethyl ether, and acetic anhydride. In all cases but one the formation of cyclopropyl acetates was observed. 4-Methyl-3-penten-2-one, methyl vinyl ketone, 2-isopropylidene-1-cyclopentanone, and 2-cyclohepten-1-one led to substituted cyclopropyl acetates. Stereospecific reactions were found with 2-ethylidene-1-cyclopentanone, 2-benzylidene-1-cyclohexanone, and methyl 1-cyclohexenyl ketone, whereas 3-penten-2-one, 3-methyl-3-buten-2-one, and 2-methyl-2-cyclohexen-1-one afforded mixtures of the isomeric cyclopropyl acetates.
These results are interpreted in terms of the intital formation of an allylic anion which undergoes electrocyclic closure. A stereospecific course is followed when geometric constraints permitted. Exceptions are discussed.
8 citations
Patent•
19 Mar 1976
TL;DR: In this article, the 3-aminophenyl)-pyridines were used in preparation of known antibacterial agents, in turn, useful in preparing known antimalarial agents.
Abstract: 3-(4 OR 3-Pyridinyl)-2-cyclohexen-1-ones (I) and their oxime derivatives are useful in preparing (3-aminophenyl)-pyridines, in turn, useful in preparing known antibacterial agents. Also shown is the preparation of I by starting with the reaction of methyl vinyl ketone with either 1-(pyridinyl)-1-(lower-tertiary-amino)-ethylene (II) or lower-alkyl 3-(pyridinyl)-3-oxopropanoate. Also shown is the process of converting I to its oxime, acylating the oxime and heating the acylated oxime under acidic conditions to produce N-(lower-acyl)-3-(pyridinyl)-aniline (VII), and hydrolyzing VII under aqueous alkaline conditions to produce the corresponding 3-(pyridinyl)aniline.
6 citations
TL;DR: In this article, the primary processes of the photolyses of acetone, methyl ethyl ketone, and methyl vinyl ketone have been studied using a high intensity UV light beam and collision-free photochemical reactor incorporated in the ionsource of a mass spectrometer.
Abstract: The primary processes of the photolyses of acetone, methyl ethyl ketone, and methyl vinyl ketone have been studied using a high intensity UV light beam and collision-free photochemical reactor incorporated in the ionsource of a mass spectrometer. Photofragment radicals are directly detected from the mass spectrum of the photolyte flow and the primary processes are determined. Mass spectrum of acetyl radical has been obtained in addition to the mass spectra of hydrocarbon free radicals reported in previous papers. As for the ketones investigated, C–C bond rupture between acetyl and the remainder of the molecule is found predominant in the primary process of the photolysis in the region 290–320 nm.
5 citations
TL;DR: The Birch reduction of 2,7-dimethoxy-3-isopropylnaphthalene (IIb) was made from IIa in five steps, followed by acid hydrolysis yielded the tetralone IIIa and the latter was carboxymethylated to IIIb by reaction with dimethyl carbonate and sodium hydride as mentioned in this paper.
Abstract: The Birch reduction of 2,7-dimethoxy-3-isopropylnaphthalene (IIb), which itself was made from IIa in five steps, followed by acid hydrolysis yielded the tetralone IIIa and the latter was carboxymethylated to IIIb by reaction with dimethyl carbonate and sodium hydride. Michael condensation of IIIb with methyl vinyl ketone yielded the unsaturated ketone IV. The tricyclic ketone IV on methylation followed by thioketalisation gave the thioketal IXa and the latter on Raney nickel desulfurisation yielded Ic.
5 citations
TL;DR: In this article, a general method of synthesis of the title compounds was proposed, based on the reaction of methyl 7methoxy-2-oxotetralin-1-carboxylate (2a) with methyl vinyl ketone in the presence of benzyltrimethylammonium methoxide catalyst.
Abstract: The reaction of methyl 7-methoxy-2-oxotetralin-1-carboxylate (2a) with methyl vinyl ketone in the presence of benzyltrimethylammonium methoxide catalyst yielded the expected tricyclic keto alcohol (3a) and the latter on dehydration with p-toluenesulphonic acid gave the unsaturated ketone (la). This constitutes a general method of synthesis of the title compounds. When sodium methoxide was used as the catalyst in the above reaction, (la) was not obtained.
4 citations
Patent•
01 Nov 1976
TL;DR: In this article, a water-soluble fluorescent coating material capable of coating on various kinds of fibers, glass, etc. is presented, which is preparaed by reacting polyvinyl alcohol (PVA) with methyl vinyl ketone under the condition of a specified pH.
Abstract: PURPOSE:A water-soluble fluorescent coating materials capable of coating on various kinds of fibers,glass,etc.preparaed by reacting polyvinyl alcohol (PVA) with methyl vinyl ketone under the condition of a specified pH.
Patent•
01 Nov 1976
TL;DR: In this article, the 3-aminophenyl)-pyridines were used in preparation of known antibacterial agents, in turn, useful in preparing known antibiotics, such as 1-(pyridine)-acetyl-3-oxopropanoate.
Abstract: 3-(4- OR 3-Pyridinyl)-2-cyclohexen-1-ones (I) and their oxime derivatives are useful in preparing (3-aminophenyl)-pyridines, in turn, useful in preparing known antibacterial agents. Also shown is the preparation of I by starting with the reaction of methyl vinyl ketone with either 1-(pyridinyl)-1-(lower-tertiary-amino)-ethylene (II) or lower-alkyl 3-(pyridinyl)-3-oxopropanoate. Also shown is the process of converting I to its oxime, acylating the oxime and heating the acylated oxime under acidic conditions to produce N-(lower-acyl)-3-(pyridinyl)-aniline (VII), and hydrolyzing VII under aqueous alkaline conditions to produce the corresponding 3-(pyridinyl)aniline.
Patent•
14 Jun 1976
TL;DR: In this paper, a Diels-Alder-type reaction involving methyl vinyl ketone and compounds having the structure ##STR1## wherein one of the two lines denoted by dots represents an additional bond was performed.
Abstract: Novel trimethyl-acetyl-octalins mixtures are prepared by a Diels-Alder-type reaction involving methyl vinyl ketone and compounds having the structure ##STR1## wherein one of the two lines denoted by dots represents an additional bond. The novel compounds possess unique and unexpected desirable olfactory properties.
Patent•
04 May 1976
TL;DR: Condensed ring polycyclic aromatic beta-alcohols are produced by a process which includes initially reacting a cyclic ketone such as cyclohexanone with a secondary amine to yield an enamine of the cyclical ketone as discussed by the authors.
Abstract: Condensed ring polycyclic aromatic beta-alcohols are produced by a process which includes initially reacting a cyclic ketone, such as cyclohexanone with a secondary amine to yield an enamine of the cyclic ketone. The enamine is thereafter reacted with an ethylenically unsaturated ketone, such as methyl vinyl ketone, to yield a condensed ring ketone such as octalone which is thereafter dehydrogenated, preferably with a copper chromite catalyst to yield a pure aromatic beta-alcohol such as beta-naphthol.
TL;DR: Amino derivatives of 1,3-diarylbenzo[f]quinoline were synthesized and subjected to reaction with methyl vinyl ketone in the presence of catalytic amounts of concentrated HCl to give the corresponding (3′-oxobutyl) aminophenyl derivatives as mentioned in this paper.
Abstract: Amino derivatives of 1,3-diarylbenzo[f]quinoline were synthesized and subjected to reaction with methyl vinyl ketone in the presence of catalytic amounts of concentrated HCl to give the corresponding (3′-oxobutyl) aminophenyl derivatives. The electronic absorption and fluorescence spectra were studied, and the absolute fluorescence quantum yields of the synthesized compounds were determined. A relationship between the position and intensity of the absorption bands and the electron-donor substituents was uncovered, and a substantial effect of the nature of the solvent on the fluorescent spectra was established.
TL;DR: Diels–Alder adducts obtained from 6-methoxy-N-methyl-1,2,3,4,7,8-hexahydroisoquinoline with ethyl acrylate, methyl vinyl ketone, and acrylonitrile are described.
Abstract: Diels–Alder adducts obtained from 6-methoxy-N-methyl-1,2,3,4,7,8-hexahydroisoquinoline and from 7-methoxy-N-methyl-1,2,3,4,5,6-hexahydroisoquinoline with ethyl acrylate, methyl vinyl ketone, and acrylonitrile are described.
TL;DR: The synthesis of the entitled four alkaloids, which were oxindole alkaloid of Uncaria species and Mitragyna species, has been completed through several steps starting from the condensation of 2-hydroxytryptamine hydrochloride with 3, 3-dimethoxy-propionaldehyde (V) as mentioned in this paper.
Abstract: The total synthesis of the entitled four alkaloids, which were oxindole alkaloids of Uncaria species and Mitragyna species, has been completed through several steps starting from the condensation of 2-hydroxytryptamine hydrochloride (IV) with 3, 3-dimethoxy-propionaldehyde (V). The condensation product (XV) was submitted to the Michael addition with methyl vinyl ketone, followed by acid treatment to give the α, β-unsaturated ketones (XIVa, b) as two stereoisomers. The isomer (XIVb) was condensed with methyl malonate to yield the ester (XXb), which was hydrogenated with Adams' catalyst to XXIb. The compound (XXIb) was treated with dil. sulfuric acid to give the lactones (XXIIa, b) as two spiro-iso-mers, the isomer (XXIIa) of which in turn, was heated with the aminal ester, then stirred with 5% MeOH-HCl, refluxed with aq. dioxane and heated with PPA to afford (±)-for-mosanine (IIIa) and (±)-isoformosanine (IIIb). Similarly, the lactone (XXVa) which was obtained from (XXb) by reduction with NaBH4 and hydrolysis with acid, gave (±)-mitraphylline (IIa) and (±)-isomitraphylline (IIb).
TL;DR: In this article, eleven structurally different α, β-unsaturated ketones were subjected to the Clemmensen reduction under anhydrous conditions using amalgamated zinc, hydrogen chloride in a solution of ethyl ether, and acetic anhydride.
Abstract: Eleven structurally different α, β-unsaturated ketones were subjected to the Clemmensen reduction under anhydrous conditions using amalgamated zinc, hydrogen chloride in a solution of ethyl ether, and acetic anhydride. In all cases but one the formation of cyclopropyl acetates was observed. 4-Methyl-3-penten-2-one, methyl vinyl ketone, 2-isopropylidene-1-cyclopentanone, and 2-cyclohepten-1-one led to substituted cyclopropyl acetates. Stereospecific reactions were found with 2-ethylidene-1-cyclopentanone, 2-benzylidene-1-cyclohexanone, and methyl 1-cyclohexenyl ketone, whereas 3-penten-2-one, 3-methyl-3-buten-2-one, and 2-methyl-2-cyclohexen-1-one afforded mixtures of the isomeric cyclopropyl acetates.
These results are interpreted in terms of the intital formation of an allylic anion which undergoes electrocyclic closure. A stereospecific course is followed when geometric constraints permitted. Exceptions are discussed.
TL;DR: In this paper, a new vinyloxyborane derivative, Id, was found to be formed in reaction of phenyl di-n-butylthioboronite (II) with methyl vinyl ketone.
Abstract: A new vinyloxyborane derivative, Id, was found to be formed in reaction of phenyl di-n-butylthioboronite (II) with methyl vinyl ketone. In order to explore its utilization in organic synthesis, the reactivity of Id and other known vinyloxyboranes was variously examined. Id and Ie gave β-hydroxyketones (IVa–c, Va–d) in fairly good yields when they were allowed to react with carbonyl compounds. The reaction of Ia′ and Ib with nitriles, followed by hydrolysis, afforded β-iminothioates (VIa–c) and β-ketoesters (VIIa–d) respectively. It was also found that the borane (Ib) reacted with formates or formamides at room temperature to give ethyl α-formylhexanoate.
TL;DR: The Birch reduction of 2,7-dimethoxy-3-isopropylnaphthalene (IIb) was made from IIa in five steps, followed by acid hydrolysis yielded the tetralone IIIa and the latter was carboxymethylated to IIIb by reaction with dimethyl carbonate and sodium hydride.
Abstract: The Birch reduction of 2,7-dimethoxy-3-isopropylnaphthalene (IIb), which itself was made from IIa in five steps, followed by acid hydrolysis yielded the tetralone IIIa and the latter was carboxymethylated to IIIb by reaction with dimethyl carbonate and sodium hydride. Michael condensation of IIIb with methyl vinyl ketone yielded the unsaturated ketone IV. The tricyclic ketone IV on methylation followed by thioketalisation gave the thioketal IXa and the latter on Raney nickel desulfurisation yielded Ic.
TL;DR: In this article, the thermischen Dimerisierung von Acrolein (Ia) und Methylvinylketon (Ib) wird jeweils selektiv nur ein Dihydropyran (II) gebildet.
Abstract: Bei der thermischen Dimerisierung von Acrolein (Ia) und Methylvinylketon (Ib) wird jeweils selektiv nur ein Dihydropyran (II) gebildet.
TL;DR: In this article, the primary processes of the photolyses of acetone, methyl ethyl ketone, and methyl vinyl ketone have been studied using a high intensity UV light beam and collision-free photochemical reactor incorporated in the ionsource of a mass spectrometer.
Abstract: The primary processes of the photolyses of acetone, methyl ethyl ketone, and methyl vinyl ketone have been studied using a high intensity UV light beam and collision-free photochemical reactor incorporated in the ionsource of a mass spectrometer. Photofragment radicals are directly detected from the mass spectrum of the photolyte flow and the primary processes are determined. Mass spectrum of acetyl radical has been obtained in addition to the mass spectra of hydrocarbon free radicals reported in previous papers. As for the ketones investigated, C–C bond rupture between acetyl and the remainder of the molecule is found predominant in the primary process of the photolysis in the region 290–320 nm.