Ketones hydrocarbons methylene

In addition to its water solubility poly(vinyl pyrrolidone) is soluble in a very wide range of materials, including aliphatic halogenated hydrocarbons (methylene dichloride, chloroform), many monohydric and polyhdric alcohols (methanol, ethanol, ethylene glycol), some ketones (acetyl acetone) and lactones (a-butyrolactone), lower aliphatic acids (glacial acetic acid) and the nitro-paraffins. The polymer is also compatible with a wide range of other synthetic polymers, with gums and with plasticisers. 

Poly(methyl vinyl ketone) Acetone, methylene chloride Water, aliphatie hydrocarbons... 

Tung, H.-C., Kang, C., and Sawyer, D.T. (1992) Nature of the Reactive Intermediates from the Iron-Induced Activation of Hydrogen Peroxide Agents for the Ketonization of Methylenic Carbons, tlie Monooxygenation of Hydrocarbons, and the Dioxygenation of Arylolefins, J. Am. Chem. Soc. 114, 3445-3455. 

Mimoun and Roch used hydrazobenzene (PhNHNHPh) for oxygenation of cyclohexane, cyclohexene, and toluene." The most active complex was formed from FCCI2 and carboxylic acid in the presence of hydrazobenzene. Davis et al. used Fepy4Cl2 and PbC02H for the same reaction and proposed the hydroperoxide complex [Fe "(OOH) PhNNHPh)] as an active species."" Sheu et al. used Fe" complexes (Fe(PA) or Fc(DPAH)2) (PA picolinato) for the monooxygenation of saturated hydrocarbons, especially ketonization of methylenic carbons. "" This system was applied to the hydroxylation of aromatic hydrocarbons as reaction mimic for tyrosine hydroxylase."" With phenol as a reactant, the dominant product was catechol. 

Ketones oxidize about as readily as the parent hydrocarbons or even a bit faster (32). Although the reactivities of hydrogens on carbons adjacent to carbonyl groups are perhaps doubled, the effect is small because one methylene group is missing in comparison to the parent hydrocarbon. Ketones oxidize less readily than similar primary or secondary alcohols (35). 

Solubility and Solvent Resistance. The majority of polycarbonates are prepared in methylene chloride solution. Chloroform, i7j -l,2-dichloroethylene, yy -tetrachloroethane, and methylene chloride are the preferred solvents for polycarbonates. The polymer is soluble in chlorobenzene or o-dichlorobenzene when warm, but crystallization may occur at lower temperatures. Methylene chloride is most commonly used because of the high solubiUty of the polymer (350 g/L at 25°C), and because this solvent has low flammabiUty and toxicity. Nonhalogenated solvents include tetrahydrofuran, dioxane, pyridine, and cresols. Hydrocarbons (qv) and aUphatic alcohols, esters (see Esters, organic), or ketones (qv) do not dissolve polycarbonates. Acetone (qv) promotes rapid crystallization of the normally amorphous polymer, and causes catastrophic failure of stressed polycarbonate parts. 

An aldehyde or ketone 1 can react with hydrazine to give a hydrazone 2. The latter can be converted to a hydrocarbon—the methylene derivative 3—by loss of Na upon heating in the presence of base. This deoxygenation method is called the Wolff-Kishner reduction. ... 

Besides aromatic hydrocarbons such as pyrene (above), benzanthracene (Becker et al., 1977a), benzoin derivatives (Baumann et al., 1982), aromatic and heteroaromatic ketones (Fomin et al., 1980 Baumann et al., 1985), azo dyes (Timpe et al., 1982), methylene blue (Becker et al., 1986 a Becker and Kohrs, 1990), acridine yellow... 

As a result of its highly polar character, silica gel is particularly useful in the separation of polarizable materials such as the aromatic hydrocarbons and polynuclear aromatics. It is also useful in the separation of weakly polar solute mixtures such as ethers, esters and in some cases, ketones. The mobile phases that are commonly employed with silica gel are the n-paraffins and mixtures of the n-paraffins with methylene dichloride or chloroform. It should be borne in mind that chloroform is opaque to UV light at 254 nm and thus, if a fixed wavelength UV detector is being used, methylene dichloride might be a better choice. Furthermore, chloroform is considered toxic and requires special methods of waste disposal. Silica gel is strongly deactivated with water and thus, to ensure stable retentive characteristics, the solvent used for the mobile phase should either be completely dry or have a controlled amount of water present. The level of water in the solvent that will have significant effect on solute retention is extremely small. The solubility of water in n-heptane is... 

When a hindered ketone is to be converted to a methylene derivative, the best results are obtained if potassium r-alkoxide is used as the base in a hydrocarbon solvent. Under these conditions the reaction can be carried out at elevated temperatures.243 Entries 10 and 11 illustrate this procedure. 

By indirect oxidation with electrogenerated NO3 radicals in f-butanol/ water/HN03/02, saturated hydrocarbons were oxidized to ketones with a statistical H-abstraction at the methylene... 

Somewhat less frequent than the reductions of aliphatic ketones to secondary alcohols and to hydrocarbons are one-electron reductions to pinacols. These are accomplished by metals such as sodium, but better still by magnesium or aluminum. Acetone gave 43-50% yield of pinacol on refluxing with magnesium amalgam in benzene [140], and 45% and 51% yields on refluxing in methylene chloride or tetrahydrofuran, respectively [825. ... 

Note that in long-chain ketones the hydrocarbon peaks are indistinguishable (without the aid of high-resolution techniques) from the acyl peaks, since the mass of the C=0 unit (28) is the same as two methylene units. 

The multiple cleavage modes in ketones sometimes make difficult the determination of the carbon chain configuration. Reduction of the carbonyl group to a methylene group yields the corresponding hydrocarbon whose fragmentation pattern leads to the carbon skeleton. 

The thermochemical data are likewise sparse for the methylene derivatives of the bicyclic and polycyclic ketones. For these species, we consider the difference quantity <540 which is defined as the difference of the gas-phase enthalpies of formation of the ketone of interest and the related hydrocarbon ... 

Plasticizers include the esters of a few aliphatic and aromatic mono and dicarboxylic acids, aliphatic and aromatic phosphorus acid esters, ethers, alcohols, ketones, amines, amides, and non-polar and chlorinated hydrocarbons. These additives are used in various mixtures. For their separation and qualitative detection, thin-layer chromatography (TLC) is preferred. Usually Kieselgur plates, 0.25 mm thick, activated at 110°C for 30 min, in the saturated vapor are used. Methylene chloride and mixtures of diisopropyl ether/petether at temperatures between 40 to 60°C have been successfully used as the mobile phase. Refer to Table 1. 

Hydrocarbons with methyl branching at C-ll to C-13 were isolated from Heliothis virescens (Noctuidae, Lepidoptera) 229). These compounds release a host-seeking behavior in the braconid Cardiochiles nigriceps, a Heliothis parasit. These kairomones were prepared in 1975 by Vinson et al. 229) by Wittig methylenation of the corresponding methyl ketones and subsequent catalytic hydrogenation 229). 

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