Consider the compound $\ce{Alkyl-(4 oxocyclopent-2-ene)carboxylate (A)}$. For example consider-
Now consider the operations:
$\ce{1. (A) + (i)BH3/THF (ii) H+}$
$\ce{2. (A) + H2/Pt}$
$\ce{3. (A) + H2/Pd-C}$
Products
In $1.$ ester group reduced to an alcohol.
In $2.$ double bond reduced to a single bond, and
In $3.$ double bond reduced to a single bond, ester group reduced to an alcohol.
However, on the next page addition of $\ce{(i)BH3/THF (ii) H+}$ selectively reduced carboxylic acid when both ester and carboxylic acid were present.
My questions:
$(i)$ I know that $\ce{(i)BH3/THF (ii) H+}$ can reduce carboxylic acid, but I am unaware if it can reduce ester.
$(ii)$ I only knew that, the reduction of ester in presence of carbonyl group could be done by first protecting the carbonyl group (converting it to cyclic ketal by reacting with ethylene glycol) and then using $\ce{LiAlH4}$. Is reaction $3.$ correct?
$(iii)$ Why aren't product $2.$ and $3.$ same? I've always seen the two work same.
Note:
My chemistry teacher gave me few notes for Chemistry Olympiad preparation, so I can not cite source. I don't know how to make compounds, so will completely reside on IUPAC nomenclature.