Paragraph: A carbonyl compound $P$, which gives positive iodoform test, undergoes reaction with MeMgBr…
Paragraph:
A carbonyl compound $P$, which gives positive iodoform test, undergoes reaction with MeMgBr followed by dehydration to give an olefin $Q$. Ozonolysis of $Q$ leads to a dicarbonyl compound $R$, which undergoes intramolecular aldol reaction to give predominantly $S$.
$\mathrm{P} \xrightarrow[2. \mathrm{H}^*, \mathrm{H}_2 \mathrm{O} \atop 3. \mathrm{H}_2 \mathrm{SO}_4, \Delta]{1. \mathrm{MeMgBr}} \mathrm{Q} \xrightarrow[2. \mathrm{Zn,~H}_2 \mathrm{O}]{1. \mathrm{O}_3} \mathrm{R} \xrightarrow[2. \Delta]{1. \mathrm{OH}^-} \mathrm{S}$
Question:
The structure of the carbonyl compound P, is
