Resonance and reductions with sodium borohydride

![enter image description here](https://i.stack.imgur.com/TiQOq.png)


I know that sodium borohydride doesn't work particularly well on resonance-stabilized carbonyl groups (i.e. esters) but what about this carbonyl in the center of the above picture? This appears to be somewhat resonance-stabilized ... why would sodium borohydride still work here? Sodium borohydride is a nucleophilic reagent. On the other hand the second resonance contributor I've drawn is pretty crappy; yes - it's part of an aromatic system - but it's also a carbocation. And the R' group is inductively donating (although I suspect this is a fairly minor point). 


Or does it just work in the above synthesis but not with a yield comparable to something such as sodium borohydride and formaldehyde? 


![enter image description here](https://i.stack.imgur.com/dNTzH.jpg)




Sodium borohydride is definitely strong enough to reduce an acetophenone derivative. It is likely that the resonance stabilization does reduce the reactivity of the ketone. It's not often that a sodium borohydride reduction requires 35 hours. In the cases that I have run, usually less than one hour is sufficient.


I did some quick searching of whether an isolated ketone could be reduced in the presence of an acetophenone, and I did not find an adequate example of a case where only the isolated ketone was reduced. That says to me that the reactivity difference is not that great. Perhaps someone else has come across this though.


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