Reaction of Tosylhydrazone with Base

Notice that the leaving group from nitrogen is not the familiar to sylate (Ts ) 

The carbene nature of this intermediate was detected by examination of camphor tosylhydrazone, which on heating with hydroxide gives a mixture ofcamphene and tricyclene. When the reaction was performed in acidic alcohols, such as ethylene 

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The Shapiro reaction of tosylhydrazones with base has now been extended as a route to a wider variety of functionalized olefins. Thus, treatment of tosylhydrazones, which contain only a tertiary a-hydrogen, with lithium iso-propylamide, can now yield trisubstituted olefins. The yields are only moderate, but the procedure is convenient. Regiospecifically generated tosyl-hydrazone dianions may be trapped with aldehydes and ketones to give, on neutralization, /3-hydroxytosylhydrazones further treatment with alkyl-lithium reagents yields allylic and homoallylic alcohols. These procedures are exemplified in Scheme 21. 

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