-= HS- diisobutylaluminium hydro (DIBAH) Wolff-Kishner Reduction: The imine formed from an aldehyde or ketone on reaction with hydrazine(NH,NH, )is unstable in base, and undergoes loss of N to give the corresponding hydrocarbon. H2N-NH2 H unstable alkyl car banion Clemmensen Reduction: Carbony l compounds can also be reduced by the Clemmensen reduction using zinc-mercury amalgam in the presence of acid; the mechanism most likely involves free radicals Zn(Hg) Zn(Hg) The Formation of Thioketal and Thioacetals: Ketones and aldehydes react with excess thiol in the presence of acid to give thioketals and thioacetals respectively. These compounds are smoothly reduced by Raney-Nickel to give the corresponding hydrocarWolff-Kishner Reduction: The imine formed from an aldehyde or ketone on reaction with hydrazine (NH2NH2) is unstable in base, and undergoes loss of N2 to give the corresponding hydrocarbon. Clemmensen Reduction: Carbonyl compounds can also be reduced by the Clemmensen reduction using zinc-mercury amalgam in the presence of acid; the mechanism most likely involves free radicals. The Formation of Thioketal and Thioacetals: Ketones and aldehydes react with excess thiol in the presence of acid to give thioketals and thioacetals, respectively. These compounds are smoothly reduced by Raney-Nickel to give the corresponding hydrocarbons