# Are groups other than carbonyl reduced by Clemmensen reduction?

According to my textbook, Clemmensen reduction reduces only aldehydes and ketones to alkanes. But in this question:

$\ce{Zn-Hg/HCl}$ has reduced both the ketonic and nitro group. Correct answer given is D.

So, what exactly is this reduction's mechanism? Is it an exception? If not, why isn't it stated in the books alongside the carbonyl groups?

• The paper - Diez-Cecilia, E., Kelly, B., Rozas, I., One-step double reduction of aryl nitro and carbonyl groups using hydrazine, Tetrahedron Letters (2011), doi: 10.1016/j.tetlet.2011.09.112 - discusses Wolff Kishner reduction of nitro compounds. I still find it surprising, though, that Wikipedia doesn't mention even once at least the possibility of reduction of nitro compounds by Clemenssen reduction, let alone their industrial use or whatever. – Gaurang Tandon Mar 15 '18 at 15:41