(d)The key intermediate in the reaction of an amine with nitrous acid is the corresponding dia-zonium ion.Loss of nitrogen from this diazonium ion is accompanied by a hydride shift to form a sec-ondary carbocation.Capture of isopropyl cation by water yields the major product of the reaction, 2-propanol.22.37Alcohols are converted to p-toluenesulfonate esters by reaction with p-toluenesulfonyl chloride.None of the bonds to the stereogenic center is affected in this reaction.Displacement of the p-toluenesulfonate leaving group by sodium azide in an SN2 process and pro-ceeds with inversion of confguration.Reduction of the azide yields a primary amine. A nitrogen–nitrogen bond is cleaved; all the bonds tothe stereogenic center remain intact.22.38(a)The overall transformation can be expressed as RBr →RCH2NH2. In many cases this can becarried out via a nitrile, as RBr → RCN → RCH2NH2. In this case, however, the substrate is1-bromo-2,2-dimethylpropane, an alkyl halide that reacts very slowly in nucleophilic substi-
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