Organomagnesium compounds, reaction

Organohthium and organomagnesium compounds find their chief use m the prepa ration of alcohols by reaction with aldehydes and ketones Before discussing these reac tions let us first examine the reactions of these organometallic compounds with proton donors... 

Anhydrous diethyl ether is the customary solvent used when preparing organomagnesium compounds. Sometimes the reaction does not begin readily, but once started, it is exothermic and maintains the temperature of the reaction mixture at the boiling point of diethyl ether (35°C). 

Grignard reagent (Section 14.4) An organomagnesium compound of the type RMgX formed by the reaction of magnesium with an alkyl or aryl halide. 

Reactions of Enamine Salts with OrganometalUc Compounds Organolithium and organomagnesium compounds react with enamine salts to give amines substituted on the ix-carbon atoms. The treatment of. -dehydroquinolizidinium perchlorate (163) with alkylmagnesium halides gives 9-alkylated quinolizidines (164) (252,256). Formation of... 

A related cleavage reaction (165 166) occurs on the treatment of isoxazoles with organomagnesium compounds.This reaction considerably hinders the use of the Grignard reaction in the isoxazole series (see Section IV,D) in it the activity of the organo-... 

The cleavage of the isoxazole ring by organomagnesium compounds may proceed by either one or both of two alternative mechanisms. Magnesium subhalides produced during the associated reaction may act as reducing agents as proved in specific cases.Another possibility is that the reduction involves a six-membered cyclic complex (171). 

Under the conditions used for the reductive cleavage of the O—N bond in isoxazoles, a similar reaction readily occurs with isoxa-zolines, e.g. on treatment with organomagnesium compounds and on catalytic hydrogenation.- Hydrogenolysis of the O—N bond (180 181 182 183) was used to elucidate the structure of isoxa-zolones from -ketoesters. -... 

The organozinc compound 2 is less reactive than an organomagnesium compound the addition to an ester carbonyl group is much slower than the addition to an aldehyde or ketone. Nevertheless the addition of 2 to the carbonyl group of unreacted a-halo ester 1 is the most frequently observed side-reaction ... 

The reaction of Grignard reagents with carbonyl compounds has no direct biological counterpart, because organomagnesium compounds are too... 

Copper (I) chloride, reaction with an organomagnesium compound, 50, 98... 

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