I did an experiment, reducing the following selectivity to target either functional group
{MOD Edit: snip out monster link to Google image search}
1) using Sn/HCl to reduce the NO2 group to NH2
2) using NaBH4 to reduce the carbonyl to an alcohol
In both cases the choice of reducing agent is selective
My understanding is that the NaBH4 is too mild to reduce the NO2 group
But I am not sure why the Sn/HCL doesn't reduce carbonyls?
Any suggestions much appreciated