' A ' and ' B ' respectively are:
$
\begin{aligned}
& \text { A } \frac{(1) \mathrm{O}_3}{(2) \mathrm{Zn}-\mathrm{H}_2 \mathrm{O}} \text { Ethane-1,2-dicarbaldehyde + Glyoxal/Oxaldehyde } \\
& \text { B } \frac{(1) \mathrm{O}_3}{(2) \mathrm{Zn}-\mathrm{H}_2 \mathrm{O}} \text { 5-oxohexanal }
\end{aligned}
$
