Ketones nitro compounds

Cyanation of ketones, nitro compounds, or benzylic compounds... 

Michael addition to unsaturated amides. This system (1 equiv. of each) effects Michael addition of ketones, nitro compounds, ethyl cyanoacetate, and diethyl malonate to a,(3-unsaturated amides. Addition to methacrylamides is interesting because the final products are glutarimides or dihydropyridinones. 

Reduction. An early report2 stated that aldehydes and a-hydroxy ketones are reduced by this reagent but that ketones, nitro compounds, carboxylic acids, and esters are not reduced. Borch and Durst,3 however, found that some ketones are reduced, but more slowly than with sodium borohydride. One advantage over the latter reagent is that lithium cyanohydridoborate is stable in acid up to pH 3 and hence can be used for reduction of groups sensitive to high pH (e.g., thiamine). 

Numerous studies have shown that low hydrogen overpotential electrically conducting catalysts (e.g., Raney nickel, platinum and palladium on carbon powder, and Devarda copper) can be used to electrocatalyticaUy hydrogenate a variety of organic compounds including benzene and multiring aromatic compounds, phenol, ketones, nitro compounds, dinitriles, and glucose [45, 46, 54, 55, 67-71]. These reactions have been carried out in both batch and semicontinuous flow reactors in most cases, the reaction products were similar to those obtained from a traditional chemical catalytic scheme at elevated temperatures and pressures. 

Organic compounds may be detected by testing for a particular functional group (e.g., ketone, nitro compound) or for individual compounds. Tests for the more common functional groups are summarized in Table 3. Specific tests for some important individual compounds are given in Table 4. In the majority of cases, there is some previous knowledge about the origin of the sample, which may replace the necessity for complete specificity. 

Concentrated, oxidising acids such as sulfuric, nitric and chromic acids which cause decomposition the rate of decomposition may be accelerated in the presence of metals, for example, zinc and iron. Attacked by bromine and fluorine even at room temperature. Unsuitable for use in contact with aromatic and chlorinated hydrocarbons, ketones, nitro-compounds, esters and cyclic ethers these penetrate the PVC and cause marked swelling. Can have a high impact strength but can be very notch sensitive. Methylene chloride can be used to detect an under-gelled compound. 

Monohydric alcohols, aldehydes (including chloral hydrate), ketones, cinnamic acid, amines (2-naphthylaminc is odourless), nitrophenols (resemble both phenol and nitro-compound),... 

The imides, primaiy and secondary nitro compounds, oximes and sulphon amides of Solubility Group III are weakly acidic nitrogen compounds they cannot be titrated satisfactorily with a standard alkaU nor do they exhibit the reactions characteristic of phenols. The neutral nitrogen compounds of Solubility Group VII include tertiary nitro compounds amides (simple and substituted) derivatives of aldehydes and ketones (hydrazones, semlcarb-azones, ete.) nitriles nitroso, azo, hydrazo and other Intermediate reduction products of aromatic nitro compounds. All the above nitrogen compounds, and also the sulphonamides of Solubility Group VII, respond, with few exceptions, to the same classification reactions (reduction and hydrolysis) and hence will be considered together. 

Ozone converts nitro compounds, where R is alkyl or hydrogen, to aldehydes and ketones... 

In general, peroxomonosulfates have fewer uses in organic chemistry than peroxodisulfates. However, the triple salt is used for oxidizing ketones (qv) to dioxiranes (7) (71,72), which in turn are useful oxidants in organic chemistry. Acetone in water is oxidized by triple salt to dimethyldioxirane, which in turn oxidizes alkenes to epoxides, polycycHc aromatic hydrocarbons to oxides and diones, amines to nitro compounds, sulfides to sulfoxides, phosphines to phosphine oxides, and alkanes to alcohols or carbonyl compounds. 

Hypochlorous acid adds to oximes of cyclic ketones forming intermediate a-chloronitroso compounds that can be converted to nitro compounds (108). 

The two major methods of preparation are the cycloaddition of nitrile oxides to alkenes and the reaction of a,/3-unsaturated ketones with hydroxylamines. Additional methods include reaction of /3-haloketones and hydroxylamine, the reaction of ylides with nitrile oxides by activation of alkyl nitro compounds from isoxazoline AT-oxides (methoxides, etc.) and miscellaneous syntheses (62HC(i7)i). 

Base promoted 1,4-additions ol nucleophiles (usually C) to a.6-unsalurated esters, ketones, nitnies, suHones, nitro-compounds often stereoselective addition. 

Enolates of aldehydes, ketones, and esters and the carbanions of nitriles and nitro compounds, as well as phosphorus- and sulfur-stabilized carbanions and ylides, undergo the reaction. The synthetic applications of this group of reactions will be discussed in detail in Chapter 2 of Part B. In this section, we will discuss the fundamental mechanistic aspects of the reaction of ketone enolates with aldehydes md ketones. 

Analogous to DPNH (144-146), 1,4-dihydropyridines (147) act as reducing agents. For instance, the conversion of aromatic nitro compounds to amines (148) and reduction of enones to ketones (749) has been achieved. 

BF3-Et20, NaCNBHs, THF, reflux 4-24 h, 65-98% yield. Functional groups such aryl ketones and nitro compounds are reduced and electron-rich phenols tend to be alkylated with the released benzyl carbenium ion. The use of BF3 Et20 and triethylsilane as a cation scavenger is also effective." ... 

Thiophenealdehydes have been condensed with aliphatic aldehydes, methyl ketones,cyclic ketones, " benzyl cyanides,and aliphatic nitro compounds to the corresponding vinylthiophenes. By the use of potassium methylate, 2-thiophenealdehyde has been condensed with the reactive methyl groups of iV-heterocyclic compounds. Thiophenealdehydes have... 

The required nitro compounds are easy to prepare, and are useful building blocks for synthesis. Treatment with an appropriate base—e.g. aqueous alkali—leads to formation of nitronates 2. Various substituted nitro compounds, such as nitro-ketones, -alcohols, -esters and -nitriles are suitable starting materials. 

Another method for improving the reactivity of nitro compounds is provided by the double deprotonadon of nitroalkanes. In this case, the reacdon with ketones affords fi-nitro alcohols in 4Q-6Q% yield CEq.d.lQi ... 

Allylic nitro compounds are obtained by the reacdon of cyclic ketones with nitromethane in the presence of 1,2-diaminoethane fl mol% as catalyst. Because exa-cyclic nitroalkenes are rearranged to the fi)iifo-cyclic fi,Y-nitroalkenes, allylic nitro compounds are selecdvely produced fEq. 3.21. ... 

If iV,iV-dimethylethylenediamine is used as the base, allylic nitro compounds are obtained n good yields from both acyclic and alicyclic ketones fEqs. 3.22 and 3.23. "... 

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