Alcohols and Their Oxidation Products

Rubbing alcohol (isopropyl alcohol or 2-propanol) is used to clean out cuts and scrapes. 

Alcohols contain one or more hydroxyl (—OH) functional groups bonded to carbon atoms and are a major class of organic compounds. The importance of methanol, ethanol, and 2-methyl-2-propanol as fuels and fuel additives was described in Sections 12.2 and 12.5. Additional uses of these and other commercially important alcohols are listed in Table 14.3. Alcohols are classified according to the number of carbon atoms bonded directly to the —C—OH carbon as primary (one other G atom), secondary (two other C atoms), or tertiary (three other C atoms). The reactivities of these classes of alcohols are different. 

Ethanol and 1-propanol are primary alcohols. 2-Propanol, or isopropyl alcohol, is familiar to us as rubbing alcohol, a 70% solution of 2-propanol in water, sold in drugstores and grocery stores. 2-Propanol is a secondary alcohol and is one of the two structural isomers of an alcohol with three carbon atoms. 

Condensed Formula Boiling Point (°C) Systematic Name Common Name Use 

CH3OH 65.0 Methanol Methyl alcohol Euel, gasoline additive. 

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Hexa- and Poly-hydric Alcohols and their Oxidation Products. Carbohydrates and Related Compounds, J. K. N. Jones, in E. H. Rodd (Ed.), Chemistry of Carbon Compounds, Vol. IB, Chap. XX, Elsevier, Amsterdam, 1952, pp. 1224-1286. 

This is the solid residue left when turpentine is distilled for the preparation of oil of turpentine. It consists essentially of resin acids and their oxidation products and forms brittle, translucent masses with a peculiar resinous odour and a colour varying from pale yellow to dark brown D = 1 05-1 085. It is readily soluble in alcohol (1 part in 10 parts of 70% alcohol) and dissolves also in methyl or amyl alcohol, ether, acetone, benzene, chloroform, carbon disulphide or oil of turpentine in petroleum ether it is not completely soluble. It is easily and completely saponified by caustic soda solution. Addition of a drop of concentrated sulphuric add to a solution of a small quantity of colophony in acetic anhydride produces an intense violet-red or purple coloration, soon changing to yellowish-brown. Different types or grades of colophony are sold, distinguished mainly by the colour and origin. 

MonolerpeneB. M. may be considered formally as dimerization products of isoprene (2-methyl-1,3-butadiene, CsHg) and have a C,o skeleton. For biogenesis, see teipenes. The class of M. includes not only acyclic but also mono- and bicyclic hydrocarbons and their oxidation products (alcohols, aldehydes, ketones, and acids). Tri- and tetracyclic M. are very rare. The simplest acyclic M. are geraniol and nerol (see geraniol), from which mono- and bicyclic M. are formed by intramolecular cyclization. The most important caition skeletons of the monocyclic M. are illustrated in formulae 1-6. 

Trace Components The trace components of landfill gas mainly comprise a range of alkanes and alkenes, and their oxidation products (aldehydes, ketones, alcohols and esters). Waste Management Paper 26 (DoE, 1986) lists 108 compounds, or groups of compounds found in landfill gas sampled at six different landfill sites. Many of these trace compounds in landfill gas are recognised toxicants when present in air at concentrations which exceed established toxicity threshold limit values (TLVs) or the Occupational Exposure Standards (OESs) set by the Health and Safety Executive. Anyone coming into contact with landfiU gas is therefore potentially at risk from the toxic nature of the minor components, and under the Control of Substances Hazardous to Health Regulations (COSHH, 1988), landfill operators are legally responsible for the health of employees and are required to comply with OES s and exposure limits set by the Health and Safety Executive (HSE). 

The second step is the analysis of the gas mixture by any available traditional or modern instrumental techniques. Carbon monoxide and dioxide, sulphur dioxide, hydrogen chloride, hydrogen cyanide as well as saturated and unsaturated hydrocarbons and their oxidation products (such as alcohols, aldehydes, ketones, carboxylic acids) are determined mainly by gas chromatography with the occasional contribution of infrared spectroscopy and mass spectrometry. 

The purification of diethyl ether (see Chapter 4) is typical of liquid ethers. The most common contaminants are the alcohols or hydroxy compounds from which the ethers are prepared, their oxidation products (e.g. aldehydes), peroxides and water. Peroxides, aldehydes and alcohols can be removed by shaking with alkaline potassium permanganate solution for several hours, followed by washing with water, concentrated sulfuric acid [CARE], then water. After drying with calcium chloride, the ether is distilled. It is then dried with sodium or with lithium aluminium hydride, redistilled and given a final fractional distillation. The drying process should be repeated if necessary. 

When variable-valence metals are used as catalysts in the oxidation of hydrocarbons, the chain termination via such reactions manifests itself later in the process. This case has specially been studied in relation to the oxidation of paraffins to fatty acids in the presence of the K Mn catalyst [57], which ensures a high oxidation rate and a high selectivity of formation of the target product (carboxylic acids). As the reaction occurs, alcohols are accumulated in the reaction mixture, and their oxidation is accompanied by the formation of hydroxyperoxyl radicals. The more extensively the oxidation occurs, the higher the concentration of alcohols in the oxidized paraffin, and, hence, the higher is the kinetic... 

The kinetic parameters for the oxidation of a series of alcohols by ALD are shown in Table 4.1 (74). Methanol and ethylene glycol are toxic because of their oxidation products (formaldehyde and formic acid for methanol and a series of intermediates leading to oxalic acid for ethylene glycol), and the fact that their affinity for ALD is lower than that for ethanol can be used for the treatment of ingestion of these agents. Treatment of such patients with ethanol inhibits the oxidation of methanol and ethylene glycol (competitive inhibition) and shifts more of the clearance to renal clearance thus decreasing toxicity. ALD is also inhibited by 4-methylpyrazole. 

Kinetic and mechanistic investigations on the o-xylene oxidation over V205—Ti02 catalysts were carried out by Vanhove and Blanchard [335, 336] using a flow reactor at 450°C. Possible intermediates like o-methyl-benzyl alcohol, o-xylene-a,a -diol, toluic acid and phthalaldehyde were studied by comparing their oxidation product distribution with that of toluene. Moreover, a competitive oxidation of o-methylbenzyl alcohol and l4C-labelled o-xylene was carried out. The compounds investigated are all very rapidly oxidized, compared with o-xylene, and essentially yield the same products. It is concluded, therefore, that these compounds, or their adsorbed forms may very well be intermediates in the oxidation of o-xylene to phthalic anhydride. The ratio in which the partial oxidation products are formed appears to depend on the nature of the oxidized compounds, i.e. o-methylbenzyl alcohol yields relatively more phthalide, whereas o-xylene-diol produces detectable amounts of phthalan. This... 

The allylic alcohol binds to the remaining axial coordination site, where stereochemical and stcrcoelectronic effects dictate the conformation shown in Figure 6A.9 [6]. The structural model of catalyst, oxidant, and substrate shown in Figure 6A.9 illustrates a detailed version of the formalized rule presented in Figure 6A. 1. Ideally, all observed stereochemistry of epoxy alcohol and kinetic resolution products can be rationalized according to the compatibility of their binding with the stereochemistry and stereoelectronic requirements imposed by this site [6]. A... 

The oxidahon of olefins with aqueous hydrogen peroxide in methanol can produce several products, by different reachon paths double bond epoxidation, allylic H-abstraction, epoxide solvolysis, alcohol and glycol oxidation (Scheme 18.6). Normally, oxide catalysts of Group IV-Vl metals are poorly selechve, because of their acidic properhes, the inhibition they are subject to in aqueous media and homo-lytic side reachons with hydrogen peroxide. The only excephon concerns the epoxidahon of a,(3-unsaturated alcohols and acids, which are able to bind on the... 

Oxidations. Oxidation of alcohols and their trimethylsilyl ethers at room temperature affords carbonyl products. Copper(ll) nitrate-dinitrogen tetroxide can also be used. 

Barrett, G. C. (1993) in Second Supplements to the 2nd Edition of Rodd s Chemistry of Carbon Compounds, Volume 1, Part D Dihydric alcohols, their oxidation products and derivatives, Ed. Sainsbury, M., Elsevier, Amsterdam, pp. 117-66... 

Elmore, D. T. (1993) in Second Supplements to the 2nd Edition of Rodd s Chemistry of Carbon Compounds, Volume 1, Part D Dihydric alcohols, their oxidation products and derivatives, Ed. Sainsbury, M., Elsevier, Amsterdam, pp. 167-211 Elmore, D. T. (1995) in Amino Acids, Peptides, and Proteins, A Specialist Periodical Report of The Royal Society of Chemistry, Vol. 26, Ed. Davies, J. S., Royal Society of Chemistry, London (preceding volumes cover the literature of peptide chemistry back to 1969 (Volume 1))... 

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