Hex$-4-$en$-2-$ol on treatment with $PCC$ gives $'A'.$ $'A'$ on reaction with sodium hypoiodite gives $'B',$ which on further heating with soda lime gives $'C'.$ The compound $'C'$ is $....... .$

Clemmensen reduction of a ketone is carried out in the presence of

Acetyl bromide reacts with excess of $CH_3MgI$ followed by treatment with a saturated solution of $NH_4Cl$ gives:

An organic compound contains $69.77 \%$ carbon,$11.63 \%$ hydrogen and the rest is oxygen. The molecular mass of the compound is $86$. It does not reduce Tollens' reagent but forms an addition compound with sodium hydrogensulphite and gives a positive iodoform test. On vigorous oxidation,it gives ethanoic acid and propanoic acid. Write the possible structure of the compound.

The product formed in the reaction is:

What is the product obtained when $m$-chlorobenzaldehyde is treated with a $50\% KOH$ solution?