Mesityl oxide is a common name of

Write the structures of the following compounds:
$(i)$ $\alpha$-Methoxypropionaldehyde
$(ii)$ $3$-Hydroxybutanal
$(iii)$ $2$-Hydroxycyclopentanecarbaldehyde
$(iv)$ $4$-Oxopentanal
$(v)$ Di-sec-butyl ketone
$(vi)$ $4$-Fluoroacetophenone

In the group $>C=O$,the carbonyl carbon is joined to other atoms by

Identify which functional group is not present in the following molecule:-
$CH_3 - C(=O) - O - CH_2 - C(=O) - CH_2 - NH_2$

What is the $IUPAC$ name of Mesityl oxide?

The $IUPAC$ name of Diacetone alcohol is