Lithium sulphite

Lithium sulphite, Li2S03.- Evaporation of the solution obtained by the action of sulphur dioxide on lithium carbonate suspended in water yields the monohydrate, Li2S03,H20 addition of alcohol or ether precipitates the dihydrate, Li2S03,2H20. The sulphite is readily soluble in water, and is susceptible to atmospheric oxidation. Heat expels the water of crystallization, and causes partial decomposition into sulphate and sulphide. Double sulphites of lithium with potassium and sodium have been prepared.1... 

Lithium cuproferrocyanide,2 Li2Cu2Fe(CN)6, is obtained by boiling cuprous cyanide with a solution of lithium ferrocyanide containing lithium sulphite, hydrogen gas being simultaneously bubbled through the solution. It crystallises in colourless, hexagonal prisms. 

H. Stamm also measured the solubilities of the salts of the alkalies in liquid ammonia —potassium hydroxide, nitrate, sulphate, chromate, oxalate, perchlorate, persulphate, chloride, bromide, iodide, carbonate, and chlorate rubidium chloride, bromide, and sulphate esesium chloride, iodide, carbonate, and sulphate lithium chloride and sulphate sodium phosphate, phosphite, hypophosphite, fluoride, chloride, iodide, bromate, perchlorate, periodate, hyponitrire, nitrite, nitrate, azide, dithionate, chromate, carbonate, oxalate, benzoate, phtnalate, isophthalate ammonium, chloride, chlorate, bromide, iodide, perchlorate, sulphate, sulphite, chromate, molybdate, nitrate, dithionate, thiosulphate, persulphate, thiocyanate, phosphate, phosphite, hypophosphite, arsenate, arsenite, amidosulphonate, ferrocyanide, carbonate, benzoate, methionate, phenylacetate, picrate, salicylate, phenylpropionate, benzoldisulphonate, benzolsulphonate, phthalate, trimesmate, mellitate, aliphatic dicarboxylates, tartrate, fumarate, and maleinate and phenol. 

The reaction of lithium enolates with molecular oxygen has been used for the a-hydroxylation of several substrates. The carbanion generated in the reaction of N,N-dialkylamides or esters with alkyl lithium reagents undergoes rapid oxidation under mild conditions when treated with molecular oxygen. The reaction produces an a-hydroperoxide intermediate which is cleanly reduced with sodium sulphite to the a-hydroxo derivatives" (equation 1). 

As shown in equation 2, the lithium enolate oxidation with O2, followed by sodium sulphite reduction, has been applied with success to oxidation of the enolate derived from 1 the nature of the reducing agent has been decisive for the direct preparation of the hepatoprotective agent Clausenamide (2). As a matter of fact, 2 forms when the treatment with O2 is done in the presence of triethyl phosphite as reducing agent, whereas sodium sulphite reduction affords compound 3. It has been postulated that the transformation 1 —3 occurs through the intermediacy of the peroxide 4. 

A kinetic study of the oxidation of sulphite ions to sulphate ions by gaseous oxygen in melts of lithium and potassium chlorides at temperatures between 414 and 504 °C has been carried out, and a possible reaction mechanism proposed.14 The interaction of oxygen at 20 °C with hydrogen sulphide presorbed at 55 °C and vice versa has been investigated.15... 

Addition methods were used for the determination of m-saturated compounds and olefins. The methods are based on the additions of bromine to unsaturated bonds, and the waves for the brominated compounds corresponding to the reduction of o, j8-dibromides (involving elimination) are measured. Their heights are proportional to the concentration of the unsaturated compound. Thus vinylchloride and 1,2-dichloroethylene were transformed into l-chloro-l,2-dibromoethane and l,2-dichloro-l,2-dibromoethane, by the action of a 3 M solution of bromine in methanol saturated with sodium bromide. The excess of bromine was removed with ammonia and the polarographic analysis was performed with sodium sulphite or lithium chloride as a supporting electrolyte. On the other hand, acetylene, vinyl-chloride, 1,2-dichloroethylene and 1,1,2-trichloroethylene were determined ) after a 24 hr reaction with bromine in glacial acetic acid (1 1). The excess bromine was removed with a stream of nitrogen or carbon dioxide. An aliquot portion is diluted (1 10) with a 3 M solution of sodium acetate in 80 per cent acetic acid and after deaeration the curve is recorded. 

Synthetic Aspects.— The extraction of reaction mixtures with aqueous sodium hydrogen sulphite has been advocated as a mild procedure for the efficient removal of norbornenone and norbornenol impurities.Deuteriated olefins can be efficiently synthesized from the corresponding arenesulphonylhydrazones. The reaction of R R CHC(R ) NNHS02Ar with an alkyl-lithium in tetramethylethylenediamine produces R R C (CR which, upon quenching with water (or D 2 O), is converted into olefin R R C=CHR (or R R C=CDR ). Treatment of the sulphonylhydrazone derived from camphor by this method gave (442) in quantitative yield with a 95 % [ H2] analysis. ... 

The reduction of a number of sultones in the bornyl and camphene series with lithium aluminium hydride can lead to a variety of products, depending on the reaction conditions. Thus 10-isobornyl sultone, when reduced in ether at room temperature, gives the corresponding sultine in 70% yield, whereas reduction in refluxing THF afforded l-mercaptomethyl-2-exo-hydroxy-7,7-dimethyl-bicyclo-[2,2,1 ]heptane. The propargylic sulphite (106), when heated to 180 °C, gave sultone (107) in 22% yield its structure was proved by A"-ray studies. The... 

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