Question

Suggest an appropriate reducing reagent for the following substrates and predict the product of the reaction:
a) 2-hexanone
b) ethyl 4-nitrobenzoate (reduction of the nitro group)
c) hexanal

Answer 1

NaH4 for a and c.
Here is a link for reducing nitro groups to various entities; take your pick. http://en.wikipedia.org/wiki/Reduction_of_nitro_compounds

Answer 2

That's NaBH4 for a and c. Sorry about the typo.

Answer 3

I don't know where in your studies you are, as there are many answers to these.

2-hexanone
can be reduced by many reducing agents and the choice will be largely governed by the cost and availability of the reagent and solvents. 2-hexanone can be reduced by sodium borohydride. This is the reagent of choice as it is easy to handle, cheap and the reduction can be done in say ethanol. Another reagent such as LiAlH4 is more expensive, more difficult to handle and requires very dry solvents.
Products are (+/-)hexan-2-ol. There are also reduction systems that will give more of one optical isomer than the other.


Hexanal can also be reduced by sodium borohydride. Product is hexan-1-ol.

To reduce just the nitro group in ethyl 4-nitrobenzoate requires a mild reducing agent. It can be done by a dissolving metal reduction (Fe in an acid) or by a metal catalyst and hydrogen (Pd on C/H2).
There are also some exotic reagents reagent that will do this reduction such as
Co2(CO)8