Organic alcohols and acids

Ethanol can also be produced in a BES. Steinbusch et al. reported on the biological reduction of acetate with hydrogen to ethanol [151]. To stimulate acetate reduction at the cathode with mixed microbial cultures, they applied a cathode potential of —0.55 V. Four major products were formed at the cathode ethanol, hydrogen, n-butyrate, and the non-reversible reduced methylviologen. Ethanol production had a coulombic efficiency of 49%. The highest rate of ethanol production was 60 mgm cathodic compartment day V Hydrogen was produced at 0.012 Nm  

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Carbohydrates, organic alcohols, and acids Cations Porins... 

Most studies of the solution gas interface have involved organic compounds, for example, organic alcohols and acids. These dissolve in water to some extent as a result of the polar group. However, the alkyl group in the molecule is hydro-phobic, so that the solute molecules are always found in excess at the solution air interface. The accumulation of the organic molecule means that its surface excess is positive so that the interfacial tension of the solution decreases as the concentration of the organic molecule increases. An example of data for the straight chain alcohols in the series n-butanol to n-octanol is shown in fig. 8.8. The results are presented in terms of the surface pressure H, which is defined as the interfacial tension, with respect to that for the pure solvent, that is,... 

At temperatures near the critical temperature, many organic degradation reactions are rapid. Halogenated hydrocarbons loose the halogen in minutes at 375°C (38). At temperatures typical of nuclear steam generators (271°C (520°F)), the decomposition of amines to alcohols and acids is well known (39). The pressure limits for the treatment of boiler waters using organic polymers reflect the rate of decomposition. 

Be Various organic derivatives Various alcohols and acids 69)... 

Various A1 organic derivatives A12(S04)j on aluminosilica carriers Amino alcohols Various alcohols and acids Acrylic, Methacrylic 47.69.117) 125,127, 128)... 

Alcohols form esters from inorganic acids as shown above. Like all esterifications, these reactions are reversible that is, in the presence of water and the right conditions, they revert to the original alcohol and acid. Nitrate esters are mainly used as explosives, but some have found use as diesel fuel additives. Note the difference between a nitrate ester such as ethyl nitrate (C2H5ONO2) and an organic nitro compound such as nitroethane (C2H5NO2). 

The reaction of alcohols with CO was catalyzed by Pd compounds, iodides and/or bromides, and amides (or thioamides). Thus, MeOH was carbonylated in the presence of Pd acetate, NiCl2, tV-methylpyrrolidone, Mel, and Lil to give HOAc. AcOH is prepared by the reaction of MeOH with CO in the presence of a catalyst system comprising a Pd compound, an ionic Br or I compound other than HBr or HI, a sulfone or sulfoxide, and, in some cases, a Ni compound and a phosphine oxide or a phosphinic acid.60 Palladium(II) salts catalyze the carbonylation of methyl iodide in methanol to methyl acetate in the presence of an excess of iodide, even without amine or phosphine co-ligands platinum(II) salts are less effective.61 A novel Pd11 complex (13) is a highly efficient catalyst for the carbonylation of organic alcohols and alkenes to carboxylic acids/esters.62... 

Wood contains a small proportion (usually less than 5%) of components which are extractable by organic solvents such as ethanol or dichloromethane. The proportion of these extractives varies in hardwoods and softwoods and also between species. Although many of these substances are removed during the chemical pulping process, some may still be retained in the final sheet of paper. Their chemical composition is very varied, and they include alkanes, fatty alcohols and acids (both saturated and unsaturated), glycerol esters, waxes, resin acids, terpene and phenolic components. The proportion which remains in pulp and paper depends upon the pulping process used. In general, acidic components such as the resin and fatty acids are relatively easily removed by alkali by conversion to their soluble... 

Lipase has been used in organic solvents to produce useful compounds. For example, Zark and Klibanov (8) reported wide applications of enzymes to esterification in preparing optically active alcohols and acids. Inada et al (9) synthesized polyethylene glycol-modified lipase, which was soluble in organic solvent and active for ester formation. These data reveal that lipases are very useful enzymes for the catalysis different types of reactions with rather wide substrate specificities. In this study, it was found that moditied lipase could also synthesize esters and various lipids in organic solvents. Chemically moditied lipases can help to solve today s problems in esteritication and hopefully make broader use of enzymatic reactions that are attractive to the industry. 

Lipases play an important role in organic synthesis and also in flavour biotechnology. Pig pancreatic extract and especially many microbial lipases are used for ester hydrolysis, esterification (alcohol and acid), transesterification (ester and... 

The goal of most studies of esterification reactions on insoluble supports has been the attachment of N-protected amino acids to polystyrene-derived alcohols. In recent years, however, the scope of esterifications has been expanded to other types of alcohol and acid. In the following section, the most important strategies for the preparation of esters on solid phase are discussed. These have been organized according to type of functionality that is initially linked to the support. 

A mixture of CO + H20 with electric discharges is not particularly effective in organic compound synthesis, but ultraviolet light that is absorbed by the water (< 1849 A) results in the production of formaldehyde and other aldehydes, alcohols, and acids in fair yields.24 The mechanism... 

Because the petrochemical industry is based on hydrocarbons, especially alkenes, the selective oxidation of hydrocarbons to produce organic oxygenates occupies about 20% of total sales of current chemical industries. This is the second largest market after polymerization, which occupies about a 45% share. Selectively oxidized products, such as epoxides, ketones, aldehydes, alcohols and acids, are widely used to produce plastics, detergents, paints, cosmetics, and so on. Since it was found that supported Au catalysts can effectively catalyze gas-phase propylene epoxidation [121], the catalytic performance of Au catalysts in various selective oxidation reactions has been investigated extensively. In this section we focus mainly on the gas-phase selective oxidation of organic compounds. 

Organic-soluble ester is brought to the reactor with the organic feed solution and freely permeates the immobilized organic liquid membrane to reach the catalyst enzyme. The ester is then hydrolyzed. The alcohol and acid products of hydrolysis are much more polar than the ester and, as such, are water soluble but relatively organic insoluble. These products diffuse to the aqueous permeate solution. The membrane both provides an active site for the reaction and separates the products of reaction from the feed [38]. 

Organic alcohols and aldehydes, for example, can be photooxidized by holes on the semiconductor surfaces to yield carboxylic acids... 

Phosphorus pentachloride is one of the most powerful reagents by which the hydroxyl of organic compounds can he replaced by chlorine. Alkyl chlorides, RC1, from alcohols, and acid chlorides, RCOC1, from acids, are often prepared by this method. The pentachloride is thereby converted first into the oxychloride, P0C13, which may itself be used for the substitution of OH by Cl. 

The most widely used in foam control are special materials called antifoams. They could be fats, oils, waxes, fatty alcohols and acids, ethers, organic compounds containing nitrogen and sulphur (alkylamines and amides, sulphides, thioethers, etc.), phosphorus organic compounds (in particular, tributylphosphate), silicon-organic compounds (silicon oils) and some non-ionic surfactants [e.g. 4,5]. 

When polar hydrocarbons or typical diphilic antifoams (fatty alcohols and acids, ether, siloxanes, etc.) are used, the stability of foam films decreases for two reasons. The first one is related to the adsorption displacement of the surfactant from the antifoam and the second one to the considerable change in the surfactant monolayer at the organic phase interface caused by the transformation of the foam film into an asymmetric film. The adsorption at the organic/water interface strongly decreases compared to the adsorption at the water/air interface. 

Owing to its powerful Lewis acidity, BF3 is an effective reagent in organic synthesis, for example, promoting the conversion of alcohols and acids to esters, the polymerization of olefins and olefin oxides, and acylations and alkylations (in a manner similar to Friedel-Crafts processes). Mechanistic studies of some reactions of the latter type, such as the ethylation of benzene by QH5F, have shown that the BF3 functions as a scavenger for HF via the formation of HBF4 and thus participates stoichiometrically rather than catalytically. 

Although several bifunctional chiral Lewis acids have been described in the literature and binding studies have been performed as outlined in Section 7.2, relatively little is known about their use as Lewis acid catalysts. Most notably, l,8-bis(dichloroboryl)naphthalene was treated with various chiral organic amines, alcohols, and acids. The resulting products were found to be efficient catalysts for asymmetric Diels-Alder reactions. The simultaneous coordination of the substrate by both Lewis acid centers is believed to play a significant role (see also Scheme 25). 

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