Benzenesulfonamides reductive cleavage

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... 

SmL, DMPU, 50-97% yield. The reaction works well for alkyl-substituted aziridines benzenesulfonamides react faster than tosyl amides. Primary toluenesulfonamides do not give clean reductive cleavage, but benzenesulfonamides do. 

Li, NH3, 75% yield or Na, NHs. Note that in the following example enone reduction is slower than benzenesulfonamide cleavage. ... 

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