Tosylhydrazine, reductions

Tosylhydrazine Reduction with tosylhydrazine and azodicarboxylic acid... 

The related borane bis(benzoyloxy)borane has also been found to be effective for tosylhydrazone reductions, examples of which are presented in Table 10 (entries 7 and 8). The latter case required the use of NaOD/D20 for efficient deuterium incorporation (instead of NaOAc/ThO). A pyridine-bo-rane complex likewise reduces tosylhydrazones in acidic ethanol/dioxane to tosylhydrazines (91-98% yields), which may be converted to hydrocarbons by treatment with KOH/MeOH or Na0Ac-3H20/CHCl3. ... 

Substituted hydrazines. Carbonyl compounds undergo reductive condensation with this reagent, which is prepared from 1,2-di-f-Boc-l-tosylhydrazine by selective hydrogenolysis. 

Benzenesulfonamide, Ar,AT-dibromo-4-methyl-(TsNBr2) bromohydrination with, 287 Benzenesulfonamides reductive cleavage, 247 synthesis of drugs, 301, 307-308 Benzenesulfonic acids. See Sulfonic acids Benzenesulfonic acid, 4-methyl-, esters (tosylates) alkyl a-synthons, 16, 24, 47, 93 fragmentation of, 89 rearrangement of, 32 reductive cleavage of, 114, 202-203 —, 4-methyl-, hydrazide (tosylhydrazine) hydrazones of fragmentation, 89 reduction, 109... 

With a, -unsaturated carbonyl compounds, reduction of the tosyl hydrazone is accompanied by migration of the double bond. Thus, cinnamaldehyde tosylhydra-zone gives 3-phenyl-1-propene in 98% yield and the a, -unsaturated ketone 99 gives the alkene 100 (7.90). The mechanism for this reaction involves reduction of the iminium ion to the tosylhydrazine 101, elimination of p-toluenesulfinic acid... 

It has been proposed that this reaction involves the initial reduction of tosylhydrazone to tosylhydrazine, followed by the elimination of / -toluenesulflnic acid and the decomposition... 

Sodium trihydridocyanoborate in hexamethylphosphoramide provides a convenient and selective system for the reductive removal of iodo, bromo, tosyloxy, and, indirectly, hydroxy groups carbonyl oxygen can be removed in the presence of tosylhydrazine in dimethyl-formamide-sulfolane at 100-105° . Thiourea dioxide in alkaline solution has been recommended as a convenient and economical reagent for the reduction of ketones to sec. alcohols . 

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