Ketones alcohols, synthesis

Alcohol oxidation Secondary alcohol Ketone Synthesis of ketones Alcohol dehydrogenase, alcohol oxidase... 

Organoaluminum compounds such as triphenylaluminum (527) are used for ketone synthesis[387]. On the other hand, the reaction of /-BuiAl affords the corresponding alcohol 528 by reductive carbonylation[388]. 

Sasol produces synthetic fuels and chemicals from coal-derived synthesis gas. Two significant variations of this technology have been commercialized, and new process variations are continually under development. Sasol One used both the fixed-bed (Arge) process, operated at about 240°C, as weU as a circulating fluidized-bed (Synthol) system operating at 340°C. Each ET reactor type has a characteristic product distribution that includes coproducts isolated for use in the chemical industry. Paraffin wax is one of the principal coproducts of the low temperature Arge process. Alcohols, ketones, and lower paraffins are among the valuable coproducts obtained from the Synthol process. 

Tnflrc anhydride is a useful reagent for the preparation of covalent triflate esters from alcohols, ketones, and other organic substrates [66] In many cases, very reactive triflates can be generated m situ and subjected to subsequent transformation without isolation [94, 95, 96, 97] Typical examples are cyclization of amides into dihydroisoqumolines (equation 45) and synthesis of Al-hydroxy-a-amino acid denvatives (equation 46) via the intermediate covalent triflates... 

Alkyne-nitrile cyclotrimerization is a powerful synthetic methodology for the synthesis of complex heterocyclic aromatic molecules.118 Recently, Fatland et al. developed an aqueous alkyne-nitrile cyclotrimerization of one nitrile with two alkynes for the synthesis of highly functionalized pyridines by a water-soluble cobalt catalyst (Eq. 4.62). The reaction was chemospecific and several different functional groups such as unprotected alcohols, ketones, and amines were compatible with the reaction.119 In addition, photocatalyzed [2+2+2] alkyne or alkyne-nitrile cyclotrimerization in water120 and cyclotrimerization in supercritical H2O110121 have been reported in recent years. 

Selectivity to desired products including light hydrocarbons, gasoline, or diesel fuel depends upon the catalyst employed, the reactor temperature, and the type of process employed. Products of the F-T synthesis are suitable for further chemical processing because of their predominantly straight chain structure and the position of the double bond at the end of the chain. By-products formed on a lesser scale include alcohols, ketones, acids, esters, and aromatics. 

Oxidation is the first step for producing molecules with a very wide range of functional groups because oxygenated compounds are precursors to many other products. For example, alcohols may be converted to ethers, esters, alkenes, and, via nucleophilic substitution, to halogenated or amine products. Ketones and aldehydes may be used in condensation reactions to form new C-C double bonds, epoxides may be ring opened to form diols and polymers, and, finally, carboxylic acids are routinely converted to esters, amides, acid chlorides and acid anhydrides. Oxidation reactions are some of the largest scale industrial processes in synthetic chemistry, and the production of alcohols, ketones, aldehydes, epoxides and carboxylic acids is performed on a mammoth scale. For example, world production of ethylene oxide is estimated at 58 million tonnes, 2 million tonnes of adipic acid are made, mainly as a precursor in the synthesis of nylons, and 8 million tonnes of terephthalic acid are produced each year, mainly for the production of polyethylene terephthalate) [1]. 

The direct coupling of Grignard reagents with carboxylic acids Is not generally useful for ketone synthesis because of the accompanying formation of tertiary alcohols. An exception is the recently-published method using a nickel catalyst. In order to accomplish such a chemoselective ketone... 

Ketone synthesis. The synthesis of ketones by reaction of Grignarcj. reagents with esters is usually unsatisfactory because of formation of tertiary alcohols as byproducts. However, this secondary reaction is mainly prevented if triethylamine (large excess) is present, and reasonable yields of ketones can be obtained unless the ester is readily enolized.1... 

Similar to the Dakin-West procedure previously mentioned, the Henry nitro-aldol condensation reaction is most widely used to synthesize trifluoromethyl ketones, although there are many examples of a,a-difluoroalkyl ketones synthesized by this method (Table 6)JU 12271 The method for a,a-difluoroalkyl and trifluoromethyl ketone synthesis is identical except for the final oxidation although fluoroalkyl and a,a-difluoroalkyl ketones are easily oxidized by the Sarett method (Cr03/pyridine),[12 the corresponding trifluoromethyl ketones can only be oxidized under basic conditions (0.3 M NaOH) with KMn04Jul Also, in some of the syntheses of a,a-difluoroalkyl ketones, the nitro alcohol intermediate was protected by si-lylation with /ert-butylchlorodimethylsilane. The silyl group was later removed by TosOH prior to oxidation. The full details of this method are given in Section 15.1.4.3.2. 

The next 10 chapters are about the synthesis of carbon skeletons with two functional groups. Compounds such as 1-3 will all be treated as 1,3-difunctionalised compounds since the important thing is not the type of functional group but the relationship between them. Our logic is that all FGs can be derived from alcohols, ketones (or aldehydes) or acids by substitution and that those three can be interconverted by oxidation or reduction. 

The oxides of zinc, cadmium, manganese, nickel, cobalt, and chromium and their mixtures are satisfactory catalysts. In a later work Dolgov and Golodnikov (6) developed an activated copper catalyst and produced a mixture of esters and ketones from alcohol. The reactions proceed by ester mechanism, and at lower temperatures (275°-300°) the formation of esters predominates. This ketone synthesis is equally applicable to higher members of the primary alcohol series. 

One exception to the general application of these ketone syntheses was failure of compounds having an alpha-substituted carbon atom such as isobutyl alcohol or 2-ethylhexanol to undergo the dehydrogenation (7) condensation reaction. This failure of alpha-substituted reactants to undergo the ketone synthesis was unexpected as the aldol condensation of alpha-substituted aldehydes with one labile hydrogen atom occurs readily. 

The infrared absorption spectra of four octyl alcohols, using a cell length of 0.1 mm., are shown in Fig. 3 (a) 1-octanol, (b) 9.2 vol. % solution of 1-octanol-d in 1-octanol, (c) 1 octanol-2-d, (d) l-octanol-2-d exposed to ketone-synthesis conditions. 

A general ketone synthesis has been developed involving reaction of trimethyl(perfluorooc-tyl)silane with acid fluorides. Yields, e.g. of 23 and 24, are generally good, and conversion of these ketones into tertiary alcohol derivatives tends to be slow, in part due to rather low solubility of the long-chain ketones.47 Indeed, it is somewhat surprising that these ketones do not react readily with trialkyl(perfluoroalkyl)silanes under these conditions to give tertiary alcohol derivatives.47... 

Acetals from aldehydes or ketones and secondary alcohols. The synthesis of ketone di-rcc-alkyl acetals ordinarily proceeds in low yield. Roelofsen and van Bekkum report that such acetals can be prepared in 70 90% yield by use of type 5A molecular sieves to absorb selectively the water formed. p-Toluenesulfonic acid is used as the acid catalyst. 

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