(i) It is an example of electrophilic substitution reaction which results in the formation of a coupled product. The nucleophilic nitrogen attacks at electron rich carbon of phenol at para position as follows:

$$ A \rightarrow R \text { and } S $$

(ii) The reaction represents Pinacole-pinacolone rearrangement. In this reaction, the intermediate is carbocation.

The reaction is represented as follows:

$$ B \rightarrow T $$

(iii) It is an example of addition reaction to carbonyl group, where lithium aluminium hydride $\left(\mathrm{LiAlH}_4\right)$ adds hydrogen across carbon and oxygen of carbonyl group thus reducing it to an alcohol. Both R and S enantiomers will be formed. Hence, racemic mixture will be obtained as carbonyl carbon becomes chiral.

(C) $$ \to $$ (P, Q)

(iv) It is an example of nucleophilic substitution, where electron rich sulphur (due to lone pairs) displaces chlorine on the ring forming a bicyclic compound.

$$ D \rightarrow R $$