Showing papers on "Methyl vinyl ketone published in 1973"

Stereochemical Studies. XXIV. Asymmetric Synthesis of optically Active (+)-4-Methyl-4-phenyl-2-cyclohexenone with Enamine Alkylation using Proline Derivatives

Abstract: Alkylation of enamines prepared from 2-phenylpropanal and L-proline derivatives, with methyl vinyl ketone, was successful and gave, after hydrolysis and cyclization, optically active (+)-4-methyl-4-phenyl-2-cyclohexanone ((+)-IV). The effects of L-proline derivatives, solvents, and reaction temperature on the alkylation were discussed. Under selected conditions the optical yield reached about 50%. Asymmetric induction was clearly thermodynamically controlled.

Wool Modification by Activated Vinyl Compounds

Abstract: Wool has been modified with activated mono- and di-functional vinyl compounds in aqueous, dimethyl sulfoxide, and mixed media. Amino acid and chemical analyses showed that lysine and histidine wool side chains reacted in relative proportions dependent on the specific vinyl compound. Order of reactivity paralleled electronegativity of the activating groups: (1) vinyl sulfone (sulfone group); (2) acrylonitrile (cyano group); (3) tetramethylene diacrylate (ester groups) and N,N'-methylenebisacrylamide (amide groups). Reduced solubility in ammonia after peracetic acid oxidation suggests that some difunctional reagents form new crosslinks. Maximum weight gain was about 5%. Hand and color were good. Tear strength was impaired. Both vinyl sulfone and acrylonitrile greatly retarded the supercontraction of felts by hot dimethyl sulfoxide. Acid dyeing tests accord with some blocking of basic dyeing sites. Cross dyeing is a potential application of the observed dye resistance.

Chemische und pharmakologische Studien über Derivate des Benzo[de]chinolins (I). 8. Mitteilung über natürliche und synthetische Isochinolinderivate

Abstract: Chemical and Pharmacological Studies on Derivatives of Benzo[de]quinoline, II Spirocompounds of type V (12–18) were synthesized by a carbenium ion cyclization reaction of the intermediates 7 and 11, respectively. 7 was prepared from 2-oxocyclopentanepropionic acid via1, 2, and 4–6; 11 from the same starting material via1, 2, and 8–10. - The spiro[7H-benzo[de]quinolin-7,1′-cyclohexan]-2′-one 27 and other compounds of type VI could be synthesized from the (1-isoquinolinyl)ethyl-cyclohexanone 25: 25 is hydroxylated to the hydroxyketone 26; treatment of 26 with a mixture of sulfuric acid and oleum gives 27. The structure of 27 has been proved by transformation into the known spirocyclohexane 33. - Aporphine analogues of type VII (38, 39) were synthesized from the cyclic ketone 34via either the formylketone 35 and its methyl vinyl ketone adducts 36 and 37 or the methyl ethynyl ketone adduct 40. Compound 40 has also been cyclized to the 10-hydroxy-aporphine 42. 9 compounds of the types mentioned have been screened for hypotensive action in rats, and partly in cats and dogs. Only compound 13 · HCl proved to be (moderately) active in rats and dogs.

Rearrangements in the Diterpenoid Series. I. The Solvolysis of Methyl 15β-tosyloxy-13-isopropyl-17-noratis-13-en-18-oate

Abstract: The synthesis of methyl 15β-hydroxy-13-isopropyl-17-noratis-13-en-18-oate (14b) is described. Compound 14b was prepared from the ketone 12b, in turn derived from the Diels–Alder adduct formed between levopimaric acid (7) and α-acetoxyacrylonitrile. Solvolysis of the tosylate of 14b proceeds predominantly with rearrangement and elimination to give methyl 16-isopropylidene-7,17-secoacon-8(15)-en-18-oate (16a). This rearrangement serves as a model for the proposed biosynthetic transformation of atisine-type alkaloids into alkaloids of the aconitine series. The degradation of 16a into the unsaturated ketone 19, which contains the 19 carbons of the aconane skeleton, is described. The Diels–Alder addition of methyl vinyl ketone to levopimaric acid is reported and the adduct is shown to possess structure 8.

Copolymers of diallyldialkylammonium compounds, anion permoselective membranes based thereon and process for preparing said membranes

Abstract: Copolymers including diallyldialkylammonium compounds of the formula: WHEREIN R1 and R2 are independently selected from the group consisting of lower alkyl, halogen substituted lower alkyl and phenyl and X is OH, a halogen or an inorganic or organic anion, alkenyl monomers, such as methyl vinyl ketone and halogen containing vinyl monomers, are useful in the preparation of anion permoselective membranes.

γ‐Radiolysis of ketone polymers. II. γ‐Irradiation of styrene–methyl vinyl ketone copolymers

Abstract: γ-Radiolysis of copolymers of styrene and methyl vinyl ketone shows that the introduction of pendant carbonyl groups markedly increases the G(s) value as compared to the homopolymer of styrene. The G(x) value is only slightly affected. These efficiencies are determined by employing an established statistical theory for random crosslinking and scission coupled with gel-permeation chromatography as the analytical tool required to follow the changes in the MWD of polymers. Also the G(H2) values are unaltered by the introduction of carbonyl groups in polystyrene. These results are in marked contrast to the effects of carbonyl groups in polyethylene when subjected to γ-radiolysis and can be attributed to the protective role played by the aromatic phenyl groups in polystyrene.

Robinson annulation of 2-hydroxymethylene-ketones. A new route to spiro-diketones

Abstract: The adducts formed from methyl vinyl ketone and the 2-hydroxymethylene derivatives of cyclic ketones of ring sizes 5, 6, 7, and 1 2 have been cyclised to spiro-ketones containing the same number of carbon atoms. Cyclisation under mild conditions gives ketols, the constitution and stereochemistry of which have been investigated. Methanol containing anhydrous calcium chloride converts the adducts of ring sizes 7 and 1 2 into spiro-ethers; the C6 adduct gives differently constituted products. The spiro-ketones all have a u.v. absorption band at ca. 224 nm (Iµca. 6500) but a second band of approximately the same intensity appears at 246 nm for ring sizes 5 and 12.

Acid catalyzed, liquid phase preparation of methyl vinyl ketone

Abstract: A process for obtaining methyl vinyl ketone by reacting acetone with formaldehyde in the presence of a strong acid in the liquid phase.

Selective formation of methyl vinyl ketone from acetone and methanol with silica-magnesia base catalyst

Abstract: Silica-magnesia was examined as catalyst for the said reaction and was found to give nearly 100% selectivity. Loading of Ag as well as MnO2 resulted in an increase of the activity of the catalyst but was not detrimental to the selectivity. The course of the reaction was briefly discussed.

Preparation of methyl vinyl ketone from 3-ketobutan-1-ol

Abstract: A process for obtaining methyl vinyl ketone by heating a solution comprising about 1 to 30 weight percent 3-ketobutan-1ol, about 0.005 to 0.50 weight percent of a strong acid, and one or more inert solvents.

Stabilized vinylidene bromide

Abstract: Polybrominated hydrocarbons are stabilized by unsaturated ketones, for example, methyl vinyl ketone.

Cataiytic Dimerization of Methyl Vinyl Ketone by Transition Metal Salts-Triphenylphosphine Systems

Abstract: 3-Methylene-2, 6-heptandione (2) was obtained by the dimerization reaction of methyl vinyl ketone (1), using the catalyst, consisted of cobalt or nickel dichloride.. and triphenylphosphine in protic solvents, at room temperature and under atmosphere. The yield of 2 became constant when the molar ratio of triphenylphosphine to metal salt was above 3: 1. ln case of Rh, Ru or Pd salt and triphenylphosphine catalyst, (2) and B-ethoxymethyl ethyl ketone (3) were obtained.

Reaction of thienyldichlorophosphine withα,β-unsaturated ketones

Abstract: 1. Methyl isopropenyl ketone or methyl vinyl ketone react with thienyldichlorophosphine in the presence of acetic anhydride to respectively give 4,5-dimethyl-2-thienyl-2-oxo-l,2-oxa-4-phospholene and 5 -methyl-2-thienyl-2-oxo-1,2-oxa-4-phospholene. 2. The esters of thienyl-β-acetylalkylphosphinic acids were obtained by the reaction of 4,5-dimethyl-2-thienyl-2-oxo-1,2-oxa-4-phospholene or 5-methyl-2-thienyl-2-oxo-1,2-oxa-4-phospholene with alcohols.

Menthone/isomenthone production - from methyl vinyl ketone and mesityl oxide

Abstract: A mixt of menthone and isomenthone is produced by slowly adding methyl vinyl ketone to a mixt of excess mesityl oxide and 10-70 wt.% aqs. KOH at between 20 degrees C and the reflux temp and subsequently hydrogenating the piperitenone thus formed. The yields of piperitenone is 68% (known process gives 53-54%), expensive solvents are not used, excess mesityl oxide can be readily recovered, and the process is simple to carry out. The isomethone/menthone mixt has a purity of 98% which is of particular importance when it is to be converted into menthol for pharmaceutical and cosmetic purposes.

1-Isopropyl-3-tert-butyl-1,2-diaza-1,3-butadiene in [4 + 2]-cycloaddition reactions

Abstract: 1-Isopropyl-3-tert-butyl-1,2-diaza-1,3-butadiene (I), which is formed as a result of the reaction of α-chloropinacoline with isopropyl hydrazine, exists in the form of a mixture of cisoid and transold conformations and is extremely active in the diene synthesis with maleic anhydride, maleimide, dimethyl fumarate, and methyl vinyl ketone. The conformations of the derivatives obtained, which contain a Δ2-tetrahydropyridazine ring, were established on the basis of the PMR spectra. 1-Isopropyl-3-tert-butyl-trans-5,6-dicarbomethoxy-Δ2-tetrahydropyrid-azine was obtained from dimethyl fumarate and I; this was confirmed by a comparison of data on it with the characteristics of the cis isomer, synthesized by the action of diazomethane on the anhydride of 1-isopropyl-3-tert-butyl-Δ2-tetrahydropyridazine-5,6-dicarboxylic acid.