Showing papers on "Methyl vinyl ketone published in 1983"
TL;DR: In this paper, a Michael-type reaction L-ascorbic acid (1) undergoes addition to acrolein to give the tricyclic hemiacetal lactone (3) was studied by a combination of NMR and IR spectroscopy.
50 citations
TL;DR: In this article, the use of polymer-supported chiral quaternary ammonium salts has given substantial optical yields, achieving optical yields of ⩽27% of the S-adduct from reaction (1), whilst those catalysts prepared from cinchonine achieve optical yields (1) and (2) were all <2.5%.
Abstract: Reaction of chloromethylated crosslinked polystyrenes with cinchonidine, cinchonine, or (–)-N-methylephedrine gave polymer-supported chiral quaternary ammonium chlorides. The hydroxide, hydrogen carbonate, fluoride, and chloride forms of these polymers, and also of a commercial polymer containing achiral quaternary ammonium groups, catalyse one or more of the following Michael reactions: (1) The addition of methyl 1-oxoindan-2-carboxylate to methyl vinyl ketone, (2) the addition of ethyl 2-oxo-cyclohexanecarboxylate to methyl vinyl ketone, and (3) the addition of thio-p-cresol to cyclohex-2-enone. Catalysts prepared from cinchonidine achieve optical yields of ⩽27% of the S-adduct from reaction (1), whilst those catalysts prepared from cinchonine achieve optical yields of ⩽13% of the R-adduct. This is one of the few instances where the use of polymer-supported chiral quaternary ammonium salts has given substantial optical yields. With reactions (2) and (3) the optical yields were all <2.5%. The catalysts are chemically fragile but, at least with reaction (1), can be re-used several times.
43 citations
TL;DR: In this paper, the existence of a series of new constituents which can be considered as Diels-Alder adducts of methyl vinyl ketone and ocimene (1, 4), myrcene (9, 10) or β-far-nesene ( 11, 12), respectively, was reported.
Abstract: The occurrence of a series of new constituents which can be considered as Diels-Alder adducts of methyl vinyl ketone and ocimene (1–4), myrcene (9, 10) or β-far-nesene ( 11, 12), respectively, was reported. Furthermore, the structures of four isomeric cyclohexene derivatives could be established as adducts 21–24 of (E, Z)- and (E, E)-1,3,5-undecatrience and methyl vinyl ketone. Another series of constituents having the norbornane skeleton represents adducts 25–32, and 33–40 of methyl cyclopentadiene and 1-octen-3-one or methyl vinyl ketone, respectively. In accordance with Alder's endo-rule the endo-isomers are preponderant in the natural as well as in the synthetic mixtures. Most of these constituents could also be identified in a lavender absolute as well as in a freshly prepared hexane extract of lavender flowers (Lavandula officinalis CHAIX).
41 citations
TL;DR: In this paper, a new synthesis of the isoquinoline ring with functionalised substituents at C(3) and C(4) was proposed, which constitutes a new synthesisation of the 3-carboxylate ring.
23 citations
Journal Article•
TL;DR: Etude RX de l'adduit de Diels Alder obtenu l'ether de phenyle (acetyl-7α dimethoxy-3,6 N-methyl phenoxy-4 exo-etheno-6,14 morphinane) as discussed by the authors.
Abstract: Etude RX de l'adduit de Diels Alder obtenu a partir de l'ether de phenyle (acetyl-7α dimethoxy-3,6 N-methyl phenoxy-4 exo-etheno-6,14 morphinane)
19 citations
TL;DR: In this paper, 3-PhS(e)-(1),2-(di)halobutadienes undergo BF3 catalysed cycloadditions with methyl vinyl ketone at 25°C, to give good yields of adducts in which the regiochemistry of addition is mainly controlled by the sulfur (selenium) atom.
17 citations
TL;DR: Michael addition of α-nitroketones to methyl vinyl ketone or acrylaldehyde followed by denitration with Bu3SnH affords 1,5-dicarbonyl compounds in good yields.
Abstract: Michael addition of α-nitroketones to methyl vinyl ketone or acrylaldehyde followed by denitration with Bu3SnH affords 1,5-dicarbonyl compounds in good yields.
17 citations
16 citations
TL;DR: In this article, a new method for the synthesis of cyclopropane derivatives is described, which involves treatment of electrondeficient olefins with dibromomethane in the presence of Ni(0) complex/zinc/Lewis acid (or alkali halide) systems.
Abstract: A new method for the synthesis of cyclopropane derivatives is described. It involves treatment of electrondeficient olefins with dibromomethane in the presence of Ni(0) complex/zinc/Lewis acid (or alkali halide) systems. Ni(PPh3)4/Zn/ZnBr2 system was effective for the cyclopropanation of methyl acrylate and acrylonitrile, but was ineffective for that of methyl vinyl ketone and acrylaldehyde. Ni(COD)2/Zn/NaI system was applicable to the cyclopropanation of methyl vinyl ketone as well as to that of methyl acrylate and acrylonitrile. Alternative catalytic systems which were easy to handle were exploited, involving in situ generated Ni(0) complexes prepared from NiBr2(PPh3)2 and zinc, or nickel bromide, sodium iodide, zinc, and an olefin. Catalytic amounts of nickel compounds are sufficient for the cyclopropanation of methyl acrylate, acrylonitrile, and methyl vinyl ketone, but a 1 : 2 nickel : acrylaldehyde mole ratio results in the best yield. A mechanism is proposed which involves metallacyclobutane as an ...
15 citations
15 citations
TL;DR: In this article, the HSAB theory was used to explain the 1,2-addition properties of organic compounds such as acrolein, methyl vinyl ketone, benzalacetone, chalcone, and 2-cyclohexen-1-one.
Abstract: Organoytterbium iodide σ complexes (RYbl) react with α,β-unsaturated carbonyl compounds such as acrolein, methyl vinyl ketone, benzalacetone, chalcone, and 2-cyclohexen-1-one to give 1,2-addition products selectively. This high selectivity is explained in terms of the HSAB theory.
TL;DR: Phenylsulphonylcyclopentadiene (7) exists mainly as the 1-isomer, and the assigned structure of its dimer has been corroborated by n.m. spectroscopy.
Abstract: Phenylsulphonylcyclopentadiene (7) exists mainly as the 1-isomer, and the assigned structure of its dimer (6) has been corroborated by n.m.r. decoupling experiments. Both the diene (7) and its cyclopentadienide anion (8) were unusually unreactive, although anion (8) rapidly perdeuteriates and undergoes Michael addition, α to the sulphonyl group, to methyl vinyl ketone, albeit in very low yield to form adduct (11). On being heated to 65 °C compound (11) rearranges, and two consecutive 1,5-shift products have been tentatively identified by n.m.r. spectroscopy.
TL;DR: In this paper, a high pressure-high temperature flow apparatus at temperatures up to 420°C and pressures up to 200 bar was used for thermal dimerization of methyl acrylate to dimethyl 2-methyleneglutarate.
Abstract: Thermal dimerization of methyl acrylate to dimethyl 2-methyleneglutarate was performed in a high pressure-high temperature flow apparatus at temperatures up to 420°C and pressures up to 200 bar. The head to head dimer dimethyl 2-methyl-3-methylenesuccinate was observed, too. Methyl vinyl ketone and acrylonitrile are able to dimerize analogously.
TL;DR: In this paper, various steric, stereoelectronic, and electrostatic factors which influence the annelation of Δ2-tetrahydropyridines are discussed.
Abstract: The various steric, stereoelectronic, and electrostatic factors which influence the annelation of Δ2-tetrahydropyridines are discussed.
TL;DR: In this article, reaction en deux etapes: 1) polymerisation isotactique du propene avec des amorceurs a base de titane; 2) polymerization anionique de la methylvinylcetone avec de des chaines non vivantes de polypropene.
Abstract: Reaction en deux etapes: 1) polymerisation isotactique du propene avec des amorceurs a base de titane; 2) polymerisation anionique de la methylvinylcetone avec des chaines non vivantes de polypropene
TL;DR: In this paper, the effect of pressure on the binary copolymerization of St-MAMMA is discussed, and it appears that in case of conjugated monomers reactivity decreases as the electron-donating character of the substituents increases.
Abstract: Synopsis This article describes the copolymerization of methyl vinyl ketone (MVK), methyl acrylate (MA), and methyl methacrylate (MMA) with styrene (St) as reference monomer at 3.4 MPa and 335 K with toluene as solvent. In addition, the effect of pressure on the binary copolymerizations of St-MAMMA is discussed. It appears that in case of conjugated monomers reactivity decreases as the electron-donating character of the substituents increases, whereas the reverse is found in unconjugated monomers. This is explained by the finding that in conjugated monomers resonance effects induced by polar factors play a dominant role, whereas in unconjugated monomers mainly polar factors are governing the relative reactivities. The r values at 3.4 MPa are compared with those predicted by means of the Q-e scheme and Patterns. No definite conclusions could be drawn about the applicability and validity of either scheme, although Patterns shows excellent result in case of the H function of Mayo. In vinyl ester copolymerizations and Le Noble and Asano’s example of the Menshutkin reaction one single factor (polarity and steric hindrance, successively) dominates AG#, AG, and AV#. This allows a straightforward interpretation of the results with the Hammond postulate and is in full agreement with Evan’s potential-energy calculations. In conjugated monomers, however, an interplay of resonance and polar factors is found. The general validity of these findings needs further experimental and theoretical support.
TL;DR: In this paper, it was reported that 4,6,11,11a-tetrahydro-1H-benzo[b]quinolizin-2(3H)-ones are produced when N-benzylaminoacetaldehyde dialkyl acetals react with methyl vinyl ketone in acid solution.
Abstract: Some time ago it was reported that 4,6,11,11a-tetrahydro-1H-benzo[b]quinolizin-2(3H)-ones are produced when N-benzylaminoacetaldehyde dialkyl acetals react with methyl vinyl ketone in acid solution. These structures have now been confirmed, the scope of the reaction broadened and the conformations of the products investigated. Some of these ketones have been treated with phenyl- magnesium bromide, but no useful central nervous system activity has been found for any of the tertiary alcohols produced.
TL;DR: In this paper, a crosslinkable polymer is obtained from amorphous poly(methyl vinyl ketone) (A-PMVK) obtained by anionic polymerization of methyl vinyl ketones.
Abstract: Photocrosslinkable polymer is prepared from amorphous poly(methyl vinyl ketone) (A-PMVK) obtained by anionic polymerization of methyl vinyl ketone. The reaction of A-PMVK with cinnamoyl chloride proceeds in pyridine at 50°C. The photosensitivity of the polymer obtained is measured by infrared and Ultraviolet photometry. The polymer is of a crosslinkable type and forms cyclobutane linkage by ultraviolet irradiation. The polymer is coated on a lithographic aluminum plate and exposed to arc and high-pressure mercury lamps. Development is with benzene, and standard inking by lithography is applied. The imaging area on the plate is stable and harder than poly(vinyl cinnamate), due to intra- and intermolecular cyclization of the main chain. Many good reproductions are produced in the lithographic proofing machine. The photosensitive polymer obtained by A-PMVK is very useful in relief plates requiring etching.
TL;DR: The addition of α-nitroketones to methyl vinyl ketone or acrylaldehyde followed by denitration with Bu3SnH affords 1,5-dicarbonyl compounds in good yields as discussed by the authors.
Abstract: Michael addition of α-nitroketones to methyl vinyl ketone or acrylaldehyde followed by denitration with Bu3SnH affords 1,5-dicarbonyl compounds in good yields.
TL;DR: In this paper, a 2,3,4-trimethylthieno[2,3-b]pyridine was obtained by the reaction of 2, 3-dimethyl-5-ammoniathiophene hexachlorostannate with methyl vinyl ketone in the presence of ferric chloride and zinc chloride.
Abstract: 2,3,4-Trimethylthieno[2,3-b]pyridine was obtained by the reaction of 2,3-dimethyl-5-ammoniathiophene hexachlorostannate with methyl vinyl ketone in the presence of ferric chloride and zinc chloride.
01 Jan 1983
TL;DR: The electron rich double bonds of silyl enol ethers and Silyloxy dienes undergo a variety of cycloaddition and electrocyclic reactions as mentioned in this paper.
Abstract: The electron rich double bonds of silyl enol ethers and silyloxy dienes undergo a variety of cycloaddition and electrocyclic reactions.