# Clemmensen reduction vs. Wolff-Kishner reduction

In which cases is the Clemmensen reduction is preferred over the Wolff-Kishner reduction?

One thing is that the Clemmensen reduction is done under acidic conditions whereas the Wolff-Kishner reaction is done under basic condition, and that I think decides somewhat which to choose depending of the nature and other groups present in the reactant.

But are there any other points to keep in mind while choosing the best suitable reaction?

• hydrazine is known to produce heterocycles with 1,3-diketones. – permeakra May 27 '15 at 6:06
• Clemmensen reduction is particularly effective at reducing aryl ketones, such as those formed from Friedel-Crafts acylations. However, acid-base is the primary consideration. Also remember the Mozingo reduction as a mild alternative. – bon May 27 '15 at 11:07

The basic difference is the medium as Clemenson is in acidic medium so if $\ce{OH}$ is present so it will be attacked too, but in Wolf-Kishner it is in basic medium so $\ce{OH}$ group can be saved which is sensitive, but if there is halogen, ester, or amide group it will not tolerate the reaction.