Oxidations to alcohols

Mixed mono- and dialkyl are used as catalysts for resin curing and as intermediates for fire retardants, oil additives, antistatic agents (qv), and extraction solvents. An equimolar mixture of mono- and dialkyl acid phosphates are formed at a 1 6 mole ratio of oxide to alcohol. 

Compounds containing susceptible C—H bonds can be oxidized to alcohols. " Nearly always, the C—H bond involved is tertiary, so the product is a tertiary alcohol. This is partly because tertiary C—H bonds are more susceptible to free-radical attack than primary and secondary bonds and partly because the reagents involved would oxidize primary and secondary alcohols further. In the best method, the reagent is ozone and the substrate is absorbed on silica gel. Yields as high as 99% have been... 

The most widely used reaction of organoboranes is the oxidation to alcohols, and alkaline hydrogen peroxide is the reagent usually employed to effect the oxidation. The mechanism, which is outlined below, involves a series of B to O migrations of the alkyl groups. The R—O—B bonds are hydrolyzed in the alkaline aqueous solution, generating the alcohol. 

A comparable metabolic fate is documented for the hydraulic fluid tributyl phosphate. Following administration to rats, the Bu groups were oxidized to alcoholic, ketonic, and acidic metabolites. The oxidized Bu groups were then cleaved by enzymatic hydrolysis [103], With 2-ethylhexyl diphenyl phosphate (9.48), an interesting case of regioselectivity was noted during its in vivo metabolism in rats. Indeed, this flame retardant and plasticizer was... 

CH3 oxidation to alcohol and carboxylic acid oxidation and subsequent opening of the pyrrolidine ring 3-hydroxylation of the pyridine ring... 

The most widely used reaction of organoboranes is the oxidation to alcohols. Alkaline hydrogen peroxide is the reagent usually employed to effect the oxidation. The mechanism is outlined below. 

A lkylated aromatic hydrocarbons have been oxidized to alcohols,... 

Biologically, hydrocarbons are oxidized to alcohols or epoxides by molecular oxygen in the presence of cytochromes P-450, which contain Fe(PPIX) as a prosthetic group coordinated by a cysteinyl mercaptide (Scheme 29). 

Alkanes are oxidized to alcohols and ketones. Linear alkanes are oxidized to secondary alcohols and ketones, with good selectivity based on hydrocarbons and H202 (Table IX). 

Aliphatic Hydroxylation. Simple aliphatic molecules such as -butane, -pentane, and n-hexane, as well as alicylcic compounds such as cyclohexane, are known to be oxidized to alcohols. Likewise alkyl side chains of aromatic compounds such as cyclohexane, are known to be oxidized to alcohols, but alkyl side chains of aromatic compounds are more readily oxidized, often at more than one position, and so provide good examples of this type of oxidation. The n-propyl side chain of n-propyl benzene can be oxidized at any one of three carbons to yield 3-phenylpropan-l-ol (C6H5CH2CH2CH2OH) by -oxidation, benzylmethyl carbinol (C6H5CH2CHOHCH3) by co-1 oxidation, and ethyl-phenylcarbinol (C6H5CHOHCH2CH3) by -oxidation. Further oxidation of these alcohols is also possible. 

Alkane oxidation to alcohols, aldehydes and ketones has been extensively studied and it was found that the smaller linear alkanes show higher turnovers than the longer linear, branched and cyclic alkanes [81]. Although the turnover numbers are found to increase with the addition of methanol as a co-solvent, the general role of the co-solvent in selectivity is still not clear. Catalytic epoxidations of relatively inert alkenes such as propylene and allyl chloride were found to be facile under mild... 

Simple alkanes can be converted to esters with dialkyloxrranes. Cyclic alkanes are oxidized to alcohols with dimethyl dioxirane. " Cyclohexane was converted to cyclohexyl trifluoroacetate with di(trifluoromethyl) dioxrrane and trifluoroacetic anhydride and also with RuCl3/MeC03H/CF3C02H. Dimethyl dioxrrane converts alkanes to alcohols in some cases. Adamantane is converted to adamantyl alcohol with DDQ (p. 1710) and triilic acid. The mechanism of oxygen insertion into alkanes has been examined. ... 

Because oxidations with oxygen are free-radical reactions, free radicals should be good initiators. Indeed, in the presence of hydrogen bromide at high enough temperatures, lower molecular weight alkanes are oxidized to alcohols, ketones, or acids [5 7]. Much more practical are oxidations catalyzed by transition metals, such as platinum [5, 6, 55, 56], or, more often, metal oxides and salts, especially salts soluble in organic solvents (acetates, acetylacetonates, etc.). The favored catalysts are vanadium pent-oxide [3] and chlorides or acetates of copper [2, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66], iron [67], cobalt [68, 69], palladium [60, 70], rhodium [10], iridium [10], and platinum [5, 6, 56, 57]. 

Alcohol synthesis. Hydr C FjSiHj) is accomplished with oxidized to alcohols with KF-H.)... 

Dioxiranes are good selective oxidants. Some /3-diketones have been oxidized to alcohols (4.56) in 95% or higher yield.269 The dioxiranes are made and used in solution. The nickel catalyst speeds up reaction 4.56. Hydrocarbons can be functionalized (4.57) in up to 92% yield in this way.270 A dioxirane phase-transfer catalyst, produced in situ with potassium peroxymonosulfate, has been used epoxidize an olefin to an epoxide (4.58) in up to 92% yield.271... 

Glycol ethers are manufactured by adding ethylene oxide to alcohols. In these reactions, both reaction rate and product distribution are important. Reaction rate is important because the reaction is slow enough to require a large, costly reactor. Product distribution is important because the yields based on oxide and alcohols are lowered if an excess of the higher-molecular-weight by-products is formed. In this type of reaction, a tubular reactor would be desirable because it would give a better control of product distribution than a tank or tower reactor. 

Perhaps the most utilized transformation of organoboranes is their oxidation to alcohols, accomplished with basic hydrogen peroxide (H2O2, NaOH). The active reagent is the hydroperoxide anion (HOO ). Alkenes are converted to alcohols with a Markovnikov orientation (the OH group is on the more substituted carbon of the C=C moiety) of the OH group via either acid catalyzed addition of water or oxymercuration (sec. 2,10.A,B). 

Alcohol ethoxylates are obtained by addition of ethylene oxide to alcohol under pressure and heating [7-9] ... 

Oxidation of alcohols. Alcohols can be oxidized by a complex prepared by addition of CrOa (20 mmole) to dry HMPT (6 ml.). The complex oxidizes laturated primary alcohols in about 80% yield lower yields are obtained from secondary alcohols. Highest yields are obtained from c ,j3-unsaturated primary and secondary alcohols. Optimum yields require only a 2 1 molar ratio of oxidant to alcohol. 

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