Showing papers on "Methyl vinyl ketone published in 1980"

Functional polymers. III. Asymmetric Michael reactions catalyzed by cinchona alkaloid-acrylonitrile copolymers

Abstract: The enantio-differentiating abilities of cinchona alkaloid–acrylonitrile copolymers (AN–CA) in the Michael reactions were studied. The reaction of methyl indan-1-one-2-carboxylate (I) with methyl vinyl ketone in toluene at room temperature yielded product (II) in 24–42% optical yield, depending on the type and frequency of the alkaloid units on the polymeric skeleton. The catalysts were recovered from the reaction mixture by filtration and with retention of their stereoselectivities. Modification of the amino or hydroxyl group of the alkaloid moiety greatly reduced the reaction rate and optical yield. The asymmetric reactions of other donors (III–VII) with methyl vinyl ketone were also studied.

THE MICHAEL-TYPE REACTION OF LITHIUM 1-ALKYNYLTRIALKYLBORATES WITH METHYL VINYL KETONE IN THE PRESENCE OF TITANIUM TETRACHLORIDE. A NEW SYNTHESIS OF δ-DIKETONES FROM ORGANOBORANES

Abstract: 1-Alkynyltrialkylborates readily available from trialkylboranes and lithium acetylides react with methyl vinyl ketone in the presence of titanium tetrachloride followed by hydrogen peroxide oxidation under neutral conditions to give corresponding δ-diketones.

Preparation and diels–alder reactions of some functionalized isoprenes

Abstract: A convenient synthetic method for some functionalized isoprenes employing 1-bromo-2-phenylthioethane and ethyl acetoacetate as starting materials is reported. It has also been found that the dienes thus obtained gave functionalized limonene analogs by Diels–Alder reaction with methyl vinyl ketone.

SYNTHESIS OF (±)-α-AMBRINOL

Abstract: Synthesis of α-ambrinol was successfully accomplished by cyclization of dihydro-γ-ionone ethylene acetal which was prepared by the titanium(IV)-promoted reaction of 3,3-dimethyl-1-trimethylsiloxycyclohexene with methyl vinyl ketone ethylene acetal followed by exo-methylenation with triphenylphosphonium methylide.

Cellulose peroxides derived from carbonylated cellulose and hydrogen peroxide

Abstract: Cellulose peroxides derived from hydrogen peroxide and cellulose derivative into which a ketone group is introduced by reaction with methyl vinyl ketone were investigated. The amount of peroxide formed on the cellulose substrate increased linearly with increasing carbonyl content of the sample, and sulfuric acid activated the formation of peroxide. The cellulose peroxide was gradually decomposed at 60°C in aqueous medium, and the decomposition was accelerated by addition of ferrous salt or irradiation with light of λ > 300nm. Grafting was initiated by adding methyl methacrylate to the thermal decomposition system under nitrogen. The formation, stability, thermal decomposition, and structure of the cellulose peroxide were discussed in comparison with one derived from aldehyde cellulose and hydrogen peroxide.

Preparation of copolymers from styrene and some unsaturated ketones and studies on their photodestruction in a condensed phase

Abstract: A comparative photodestruction study was carried out on solid state copolymers of styrene with methyl vinyl ketone, methyl isopropenyl ketone, phenyl vinyl ketone, benzalacetone and benzalacetophenone. The photolysis of the examined copolymers was found to proceed rapidly higher destruction rates being observed with increasing the ketone concentration. The rate of light-induced destruction for the first three copolymers was markedly greater than that of the styrene-benzalacetone and styrene-benzalacetophenone copolymers. The photodestruction proceeds probably by the Norrish II mechanism. Es wurde eine vergleichende Untersuchung des Photoabbaus von Copolymeren des Styrols mit Methylvinylketon, Methylisopropenylketon, Phenylvinylketon, Benzalaceton und Benzalacetophenon im festen Zustand durchgefuhrt. Es wurde eine schnelle Photolyse der untersuchten Copolymeren festgestellt, wobei die Abbauraten mit steigender Ketonkonzentration zunahmen. Die Geschwindigkeit des lichtinduzierten Abbaus fur die ersten drei Copolymeren war merklich hoher als die der Styrol-Benzalaceton- und Styrol-Benzalacetophenon-Copolymeren. Der Photoabbau erfolgt wahrscheinlich nach dem Norrish II-Mechanismus.

4(5)-Acetyl-9,9-dimethyltricyclo-(4,4,0,1(8,10))-undec-1-ene, its preparation and use as odorant, and odorant composition containing it

Abstract: 4(5)-Acetyl-9,9-dimethyltricyclo[4.4.0.1 8.10 ]. 4 (5) -acetyl-9,9-dimethyltricyclo [4.4.0.1 8,10]:. undec-l-en, dessen Herstellung nach Diels-Alder durch Umsetzung von Nopadien mit Methylvinylketon sowie dessen Verwendung als Riechstoff und dieses enthaltende Riechstoffkompositionen. undec-l-en, whose preparation according to Diels-Alder reaction of Nopadien with methyl vinyl ketone and its use as a fragrance and fragrance compositions containing it.

Addition of organoaluminates to acrolein or methyl vinyl ketone in the presence of a stoichiometric amount of copper(ii) acetate. a convenient route to ketones and aldehydes from olefins via hydroalumination

Abstract: Organoaluminates, readily prepared by TiCl4-catalyzed hydroalumination of olefins with LiAlH4, react with acrolein or methyl vinyl ketone in the presence of a stoichiometric amount of copper(II) acetate to give the 1,4-addition product in excellent yield. The facile reactions offer a convenient method for the preparation from olefins of the corresponding aldehydes or ketones.

The michael-type reaction of lithium 1-alkynyltrialkylborates with methyl vinyl ketone in the presence of titanium tetrachloride. a new synthesis of δ-diketones from organoboranes

Abstract: 1-Alkynyltrialkylborates readily available from trialkylboranes and lithium acetylides react with methyl vinyl ketone in the presence of titanium tetrachloride followed by hydrogen peroxide oxidation under neutral conditions to give corresponding δ-diketones.