the construction of the cpr begain in 1884.
when did the construction of the cpr begin?
1884
Na
Na
"α,β"-unsaturated carbonyl tosylhydrazones can be converted into the corresponding alkenes with migration of the double bond. the reduction proceeds stereoselectively to furnish the "e" geometric isomer.





























a very mild method was developed by kabalka "et al." who used one equivalent of catecholborane to reduce "α,β"-unsaturated tosylhydrazones.





























djerassi "et al." studied the mechanism of nabhcn reduction of "α,β"-unsaturated tosylhydrazones. based on deuterium-labeling experiments, they concluded that alkene formation is initiated by hydride reduction of the iminium ion followed by double bond migration and nitrogen extrusion which occur in a concerted manner.
wolff–kishner reduction