Showing papers on "Methyl vinyl ketone published in 1986"
94 citations
TL;DR: In this article, the reaction of methyl vinyl ketone with a variety of aldehydes, catalyzed by 1,4-diazabicyclo (2.2) octane (DABCO) in tetrahydrofuran, conveniently provides the corresponding α-methylene-β-hydroxyalkanones in good yields.
78 citations
TL;DR: In this article, pure methyl vinyl ketone and acrylonitrile react with aldehydes in the presence of 1,4-diazabicyclo[2.2] octane (DABCO) to give high yields of α-methylene-β-hydroxyketones and nitriles respectively.
68 citations
TL;DR: In the presence of palladium(II) chloride, 2-bromoanilines readily react with the methyl vinyl ketone and the ethyl acrylate to produce vinylogous arylamino ketones and esters as discussed by the authors.
Abstract: In the presence of palladium(II) chloride, 2-bromoanilines readily react with the methyl vinyl ketone and the ethyl acrylate to produce vinylogous arylamino ketones and esters. A palladium(0)-assisted cyclization of the arylamino ketones and the esters leads to a formation of 3-substituted indoles.
62 citations
TL;DR: In this article, a copper chromite catalyst was used for the hydrogenation of crotonaldehyde, methyl vinyl ketone and methacrolein, and the results showed that the high polarization of these molecules led mostly to a 1,4 addition process, whereas 1,2-hydrogenation reactions were observed with dienes.
61 citations
TL;DR: The tetraene 2 is a versatile reagent for regioselective pairwise cycloadditions as discussed by the authors, and it can be used for both the 1-dimethoxymethyl group in derivatives 2 and 6 of 2,3,5,6-tetramethylidene-7-oxabicyclo[2.2.1]heptanes.
Abstract: The syntheses of 2,3-dimethylidene- and 2,3,5,6-tetramethylidene-7-oxabicyclo[2.2.1]heptanes substituted in position C(1) are reported. The 1-dimethoxymethyl group in derivatives 2 and 6 controls the regioselectivity of the Lewis-acid-catalyzed Diels-Alder additions with methyl vinyl ketone and butynone. For the EtAlCl2-catalyzed addition of methyl vinyl ketone to 6, the regioselectivity can be reversed by a small solvent modification. The tetraene 2 is a versatile reagent for regioselective ‘tandem’ cycloadditions.
22 citations
21 citations
TL;DR: In this paper, a total synthesis of (+)-pisiferol (1) has been accomplished by utilising an optically active Wieland-Miescher ketone analogue (S)-(+)-(6) bearing an angular protected hydroxymethyl group, as the key intermediate.
Abstract: A total synthesis of (+)-pisiferol (1) has been accomplished by utilising an optically active Wieland–Miescher ketone analogue (S)-(+)-(6) bearing an angular protected hydroxymethyl group, as the key intermediate. Reductive methylation of the monoacetal (7) of compound (6), followed by Huang–Minlon reduction, gives the trans-decalone acetal (9). Construction of the remaining carbocycle leading to the dodecahydrophenanthrenone (14) is achieved through five sequential reactions (deprotection, methoxycarbonylation, Michael addition with methyl vinyl ketone, demethoxycarbonylation, and intramolecular aldol cyclisation). After introduction of the 2-hydroxypropan-2-yl side-chain, dehydration followed by base-catalysed aromatisation affords pisiferol methoxymethyl ether (18). Finally, hydrolysis furnishes (+)-pisiferol (1).
13 citations
TL;DR: In this paper, the reaction of 2-ethylindole and 2-benzylindole with methyl vinyl ketone gives 1,2-dimethylcarbazole and 1-phenyl carbazole respectively.
12 citations
TL;DR: Carboxylation of ketones with carbon dioxide in the presence of magnesium chloride and triethylamine followed by reaction with methyl vinyl ketone gives satisfactory yields of Michael and Robinson annulation products.
10 citations
TL;DR: In this paper, a method for the synthesis of α, β-unsaturated compounds was developed by using methanol as a methylenylating agent, which was applied to the conversion of acetone to methyl vinyl ketone and that of methyl propionate to methyl methacrylate.
Abstract: A novel method for the synthesis of α, β-unsaturated compounds was developed by using methanol as a methylenylating agent. Methyl or methylene group at α-position of saturated ketones, esters or nitriles is converted into vinyl group by the addition of methanol over metal ion containing magnesium oxide catalysts, M-MgO [M=Cr(III), Fe(III), Al(III), Mn(II), Ni(II), Cu(II)]. The most promising application of this method is demonstrated by the selective synthesis of acrylonitrile from acetonitrile and methanol over Cr-MgO catalyst. Selectivity to acrylonitrile of more than 95% is attained at 10% conversion of acetonitrile and no deactivation of the catalyst is observed. The method was also applied to the conversion of acetone to methyl vinyl ketone and that of methyl propionate to methyl methacrylate. It was found that the step determining the rate of reaction was the abstraction of α-hydrogen from substrates by surface basic sites. Reaction mechanism and role of added metal ion are discussed.
TL;DR: The tri-isopropylphenylsulphonylhydrazone of methyl vinyl ketone undergoes the Shapiro reaction to give 2-lithiobuta-1,3-diene which reacts with aldehydes to give two-substituted dienes with high regioselectivity as mentioned in this paper.
Abstract: The tri-isopropylphenylsulphonylhydrazone of methyl vinyl ketone undergoes the Shapiro reaction to give 2-lithiobuta-1,3-diene which reacts with aldehydes to give 2-substituted dienes with high regioselectivity.
TL;DR: The structure of the clavularins A and B were shown to be cycloheptenone derivatives (2a and B) in this paper, using the Michael reaction of the lithium dienolate anion with trimethylsilyl -substituted methyl vinyl ketone.
Abstract: (±)- Clavularin B (2b) was prepared from cyclohepta-2,6-dienone (4) via a Michael reaction of the lithium dienolate anion (5a) with the trimethylsilyl -substituted methyl vinyl ketone (11). The structures of the clavularins A and B were thus unambiguously established as cycloheptenone derivatives (2a) and (2b). The Mukaiyama reaction between the silyl dienol ether (5b) and but-3-en-2-one gave 8-acetyl-4- methylbicyclo[3.2.2]nonan-6-one (9).
TL;DR: In this article, a convenient synthesis of β-bisabolene, the component of the essential oil of lemon, lime, bergamot, and so on, was described, starting from methyl vinyl ketone and isoprene via 1- (4-methyl-3-cyclohexenyl) -1-ethanone N, N-dimethylhydrazone in five steps.
Abstract: A convenient synthesis of β-bisabolene, the component of the essential oil of lemon, lime, bergamot, and so on is described. The bisabolene was synthesized starting from methyl vinyl ketone and isoprene via 1- (4-methyl-3-cyclohexenyl) -1-ethanone N, N-dimethylhydrazone in five steps.
TL;DR: The addition of two equivalents of methyl vinyl ketone to dimedone, followed by acid-catalyzed cyclization give in 64% overall yield a strained tricyclic molecule with a spiro ring junction.
TL;DR: In this paper, copolymerization of methyl vinyl ketone (M1) with acrylamide (M2) without catalyst was studied in tetrahydrofuran below room temperature.
Abstract: Copolymerizabilities of methyl vinyl ketone(M1) with acrylamide(M2) without catalyst were studied in tetrahydrofuran below room temperature.Under several conditions of light, the monom er reactivity ratios were obtained as follows; r1=0.70 and r2=0.79 for irradiation under room light; r1 =O.78 and r2=0.97 for unirradiation under light; r1=1.28 and r2=1.23 for irradiation under UV light. The presence of oxygen gas in the copolymerization system tends to decrease the rate of copolymerization(Rp). Meanwhile, it is interesting that Rp in unirradiated systems indicated higher value than these in the irradiated system with room light or UV light. These Rp indicated the maximum values at about 50 mol% in monomer feed, and the each monomer was not homopolymerized. These phenomena might be explained by the interaction between carbonyl group and carbamoyl group.
Patent•
28 Jan 1986
TL;DR: In this article, a cis-structure-containing polyacetylene is prepared by, for example, a method comprising polymerizing acetylene at a relatively low reaction temperature in the presence of, e.g., a Ziegler-Natta catalyst.
Abstract: PURPOSE:To obtain a partially cyclized polyacetylene excellent in durability, stability, etc., and suitable as an electrode or the like, by reacting by heating polyacetylene containing a cis structure with a carbonyl group-containing unsaturated compound. CONSTITUTION:A cis-structure-containing polyacetylene is prepared by, for example, a method comprising polymerizing acetylene at a relatively low reaction temperature in the presence of, e.g., a Ziegler-Natta catalyst. This polyacetylene is reacted with a carbonyl group-containing unsaturated compound at 100-500 deg.C according to the reaction formula to obtain a partially cyclized polyacetylene. Examples of the carbonyl group-containing unsaturated compounds which can be used include partially oxidized polyacetylene obtained by exposing polyacetylene to an oxidizing atmosphere or immersing polyacetylene in an oxidizing liquid; unsaturated ketones (e.g., methyl vinyl ketone); and unsaturated aldehydes (e.g., acrolein).
01 Jul 1986
TL;DR: In this article, an investigation of the recovery efficiencies of selected principal organic hazardous constituents (POHCs) from the Volatile Organic Sampling Train (VOST) under laboratory conditions is described.
Abstract: The report describes an investigation of the recovery efficiencies of selected principal organic hazardous constituents (POHCs) from the Volatile Organic Sampling Train (VOST) under laboratory conditions. The compounds included: vinyl chloride, carbon tetrachloride, trichloroethylene, benzene, toluene, perchloroethylene, monochlorobenzene, methyl vinyl ketone, tetrahydrofuran, and chloroform. An inhouse organic vapor generation system was used to produce atmospheres with pre-determined concentrations of the POHCs. These were sampled by the VOST. The sampling traps were desorbed and analyzed by GC/FID. The predetermined total nanograms of POHCs were compared to the total nanograms found by the analyses. Excluding vinyl chloride and methyl vinyl ketone, the overall mean percent recovery for the individual compounds ranged from 81.0 to 118.1%.
Patent•
21 Nov 1986
TL;DR: A flurine-containing cyclic compound shown by the formula I (R and R are H, aliphatic hydrocarbon, or aromatic hydrocarbon) was used as a substrate for enzyme suicide as discussed by the authors.
Abstract: NEW MATERIAL:A flurine-containing cyclic compound shown by the formula I (R and R are H, aliphatic hydrocarbon, or aromatic hydrocarbon and R further may be aliphatic hydrocarbonoxy, or aromatic hydrocarbonoxy. EXAMPLE:A compound shown by the formula II. USE:A substrate for enzyme suicide. PREPARATION:An unsaturated compound shown by the formula IV A 2- fluoroacetate shown by the formula III is reacted with an unsaturated compound such as methyl vinyl ketone, etc., shown by the formula IV in the presence of spray dried KF is H, aliphpatic or aromatic hydrocarbon oxycarbonyl) is condensed in sodium methylate and methanol at 50 deg.C for 5hr to give a compound shown by the formula VI (when R is H). This compound is dehydrated with P2O5 while heating to give a compound shown by the formula I.
TL;DR: In the presence of palladium(II) chloride, 2-bromoanilines readily react with the methyl vinyl ketone and the ethyl acrylate to produce vinylogous arylamino ketones and esters as mentioned in this paper.
Abstract: In the presence of palladium(II) chloride, 2-bromoanilines readily react with the methyl vinyl ketone and the ethyl acrylate to produce vinylogous arylamino ketones and esters. A palladium(0)-assisted cyclization of the arylamino ketones and the esters leads to a formation of 3-substituted indoles.