Search results for "Dioxolane"
showing 10 items of 40 documents
CCDC 654062: Experimental Crystal Structure Determination
2009
Related Article: G.Bentabed-Ababsa, A.Derdour, T.Roisnel, J.A.Saez, L.R.Domingo, F.Mongin|2008|Org.Biomol.Chem.|6|3144|doi:10.1039/b804856h
CCDC 688228: Experimental Crystal Structure Determination
2009
Related Article: G.Bentabed-Ababsa, A.Derdour, T.Roisnel, J.A.Saez, P.Perez, E.Chamorro, L.R.Domingo, F.Mongin|2009|J.Org.Chem.|74|2120|doi:10.1021/jo8027104
CCDC 654061: Experimental Crystal Structure Determination
2009
Related Article: G.Bentabed-Ababsa, A.Derdour, T.Roisnel, J.A.Saez, L.R.Domingo, F.Mongin|2008|Org.Biomol.Chem.|6|3144|doi:10.1039/b804856h
CCDC 688218: Experimental Crystal Structure Determination
2009
Related Article: G.Bentabed-Ababsa, A.Derdour, T.Roisnel, J.A.Saez, P.Perez, E.Chamorro, L.R.Domingo, F.Mongin|2009|J.Org.Chem.|74|2120|doi:10.1021/jo8027104
Novel inhibitors of mitochondrial respiratory chain: endoperoxides from the marine tunicate Stolonica socialis.
2001
The Mediterranean tunicate Stolonica socialis contains a new class of powerful cytotoxic acetogenins, generically named stolonoxides. In this paper, which also details the isolation and chemical characterization of a minor component (3a) of the tunicate extract, we report the potent inhibitory activity (IC(50) < 1 microM) of stolonoxides (1a and 3a) on mitochondrial electron transfer. The compounds affect specifically the functionality of complex II (succinate:ubiquinone oxidoreductase) and complex III (ubiquinol:cytochrome C oxidoreductase) in mammalian cells, thereby causing a rapid collapse of the whole energetic metabolism. This result, which differs from the properties of similar known…
Polar [3 + 2] cycloaddition of ketones with electrophilically activated carbonyl ylides. Synthesis of spirocyclic dioxolane indolinones
2008
International audience; The [3 + 2] cycloaddition reaction between carbonyl ylides generated from epoxides and ketones (ethyl pyruvate, ethyl phenylglyoxylate, isatin, N-methylisatin and 5-chloroisatin) to give substituted dioxolanes and spirocyclic dioxolane indolinones was investigated. The effect of microwave irradiation on the outcome of the reaction was studied. The thermal reaction between 2,2-dicyano-3-phenyloxirane and N-methylisatin was theoretically studied using DFT methods. This reaction is a domino process that comprises two steps. The first is the thermal ring opening of the epoxide to yield a carbonyl ylide intermediate, whereas the second step is a polar [3 + 2] cycloadditio…
(−)-(4R,5R)-4,5-Bis[hydroxy(diphenyl)methyl]-2,2-dimethyl-1,3-dioxolane
2008
[93379-48-7] C31H30O4 (MW 466.57) InChI = 1S/C31H30O4/c1-29(2)34-27(30(32,23-15-7-3-8-16-23)24-17-9-4-10-18-24)28(35-29)31(33,25-19-11-5-12-20-25)26-21-13-6-14-22-26/h3-22,27-28,32-33H,1-2H3/t27-,28-/m1/s1 InChIKey = OWVIRVJQDVCGQX-VSGBNLITSA-N (chiral shift reagent; chiral host in inclusion compounds; chiral reagent; chiral ligand for asymmetric catalysis) Alternate Name: TADDOL. Physical Data: mp: 190–192 °C1a; 195–196.5 °C1b; 192–193 °C;1c,e 193.5–195 °C;1d [α]RTd=−68.5 °(c = 1, CH3Cl);1a [α]d = −60.6 °(c = 1, CH3Cl);1b [α]20d = −67 ° (c = 1, CH3Cl);1c [α]20d = −65.1° (c = 1, CH3Cl);1d [α]20d = −64.6°(c = 1, CH3Cl)1e Solubility: soluble in toluene, cyclohexane, dichloromethane and tetra…
Some new examples of polymer modification
1985
This lecture summarizes some of our recent results about reactions with synthetic polymers. By cationic ring-opening polymerization of 4H, 7H-1,3-dioxepin a linear polyacetal containing one C-C-double bond per repeating unit is obtained. Copolymerization of this monomer with trioxane or dioxolane is possible. Various addition reactions can be carried out with these unsaturated polyacetals, polymeric epoxides being of special interest. Some other unsaturated cycloacetals are briefly mentioned. Amide moieties in linear polyamides can be modified by different reactions. Preparation and properties of poly-N-chloroamides and poly-N-trifluoroacetyl-amides are described. By reaction of metalated p…
Über den Mechanismus der Entstehung von 1.3.5-Trioxacycloheptan bei der kationischen Polymerisation von 1.3-Dioxolan
1971
Die von MIKI, HIGASHIMURA und OKAMURA beschriebene Bildung von Trioxacycloheptan wahrend der kationischen Polymerisation von Dioxolan wird durch Spuren von Wasser verursacht und ist nicht auf die von MIKI et al. postulierte backbiting-Reaktion zuruckzufuhren. Wasser fuhrt durch Polymerisationsubertragung zu Hemiformal-Endgruppen, aus welchen Formaldehyd abgespalten wird, der dann zusammen mit Dioxolan Trioxacycloheptan ergibt. Die Trioxacycloheptankonzentration steigt schon nach kurzen Polymerisationszeiten nicht weiter an und ist direkt proportional der Menge an zugesetztem Wasser; dadurch ist eine bequeme und sehr empfindliche Bestimmung des Gesamtwassergehaltes im Polymerisationsansatz m…
1968
In order to determine the concentration of active centers, polymerizations are terminated by addition of sodium alkoxide. This yields alkoxy endgroups which after acid hydrolysis of the isolated and purified polymers are determined by gaschromatography of the produced alcohol. In cationic polymerization of anhydrous formaldehyde at −78°C under certain reaction conditions a fast and quantitative initiation reaction and no kinetic chain termination have been observed. Presumably living polymers are obtained. The unexpected decrease in the rate of polymerization after a certain conversion is ascribed to hindrance of monomer diffusion in the crystalline polymer in which the active centers are i…