Ketones, from alkyl halides

Dihydropyrans 88-90 are deprotonated at the vinylic position adjacent to oxygen by t-BuLi and the resulting anions add readily to alkyl halides, aldehydes, and ketones. Subsequent acid hydrolysis provides the products expected from reaction of an oj-functionalized pentanoyl anion 88 acts as HOCH2(CH2)3CO , 89 as 0CH(CH2)3C0 , and 90 as MeCO(CH2)3CO (77TL4187 81T3997). 

Organometallic compounds or carbanions undergo a number of reactions in which the carbanion or carbanion-like moiety of the organometallic compound acts as a nucleophilic displacing agent. Examples are the formation of hydrocarbons from alkyl halides, alkyl halides from halogens, and ketones from acid chlorides or esters. The latter two reactions are closely related to the base-catalyzed condensations and are perhaps additions as well as displacement reactions. Related addition reactions are the carbonation of organometallic compounds and the addition to ketones or aldehydes. 

Mechanistic aspects of the reduction of benzyl halides at mercury have been extensively investigated [35, 38]. From the reduction of benzyl iodide at platinum, Koch and coworkers [39] obtained toluene, bibenzyl, and hydrocinnamonitrile. Electrolysis of benzyl chloride in the presence of acyl chlorides can be used to synthesize alkyl benzyl ketones [40], whereas alcohols are formed by electrolysis of... 

The a-alkylation of enolates derived from ketones with alkyl halides is a very important and frequently used method for forming new carbon-carbon bonds in organic synthesis [40]. Yet, if the a-alkylation of enolates derived from ketones with alkyl halides can be replaced by the direct reaction of ketones with alcohols, this method would provide a very useful waste-free, green route to a-alkylation, producing no side products other than water. 

C-(w-propyl)-N-phenylnitrone to N-phenylmaleimide, 46, 96 semicarbazide hydrochloride to ami-noacetone hydrochloride, 45,1 tetraphenylcyclopentadienone to diphenyl acetylene, 46, 44 Alcohols, synthesis of equatorial, 47, 19 Aldehydes, aromatic, synthesis of, 47,1 /8-chloro-og3-unsaturated, from ketones and dimethylformamide-phosphorus oxychloride, 46, 20 from alkyl halides, 47, 97 from oxidation of alcohols with dimethyl sulfoxide, dicyclohexyl carbodiimide, and pyridinium trifluoroacetate, 47, 27 Alkylation, of 2-carbomethoxycyclo-pentanone with benzyl chloride, 45, 7... 

Hydrides from carboxylic acids Carboxylic acids from hydrides Carboxylic acids from hydrides Esters from hydrides Hydrides from aldehydes Hydrides from aldehydes Alkyls from aldehydes Ketones from methylenes Ketones from ketones Alkyls from olefins Acetylenes from halides also acetylenes from acetylenes Esters from alcohols also esters from carboxylic acids Alkyls from olefins Alkyls from olefins... 

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