Tosylhydrazones ethylene derivs

Butyllithium/N, N, N, N -tetramethylenediamine Synthesis of ethylene derivs. from tosylhydrazones Shapiro reaction [Pg.488]

Ethylene derivatives from tosylhydrazones Bamford-Stevens reaction... 

Other bases may be employed, e.g. lithium hydride, sodium hydride, sodium amide or sodium in ethylene glycol with sodium in ethylene glycol, the reaction is called the Bamford-Stevens reaction. Aldehyde tosylhydrazones (200) do not form dianions with organolithiums, but the reagent adds to the carbon-nitrogen double bond to give the dilithium derivative (201) which decomposes to the organolithium compound (202). 

The base-mediated conversion of arylsulfonylhydrazones to alkenes was first observed by Bamford and Stevens in 1952.6 In a representative transformation, tosylhydrazone 3 was converted to cyclohexene (4) in quantitative yield after refluxing for 90 minutes in an alkoxide solution derived from dissolution of sodium in ethylene glycol. These reactions are believed to proceed via intermediate diazo compounds, which are transformed to alkenes by thermal elimination processes. 

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