Reaction in option (A): This reaction is an example of electrophilic substitution reaction, which results in coupled product, hence it is a coupling reaction. Reaction in option (B): This is a pinacole-pinacolone rearrangement, the intermediate is a carbocation. H3C−
OH
|
C
|
CH3
−
OH
|
C
|
CH3
−CH3
H+
→
H3C−
OH
|
C
|
CH3
−
+
O
H2
|
C
|
CH3
−CH3
−H2O
→
H3C−
OH
|
C
|
CH3
−
+
C
|
CH3
−CH3
Carbocationintermediate
Reaction in option (C): It is an example of addition reaction by carbonyl compound and both the enantiomers will be formed. Hence, a racemic mixture will be obtained.
Reaction in option (D): It is an example of intramolecular nucleophilic substitution reaction.