Match List-I with List-II

Choose the correct answer from the options given below:

(A)-(II), (B)-(I), (C)-(IV), (D)-(III)

The correct answer is Option (1) → (A)-(II), (B)-(I), (C)-(IV), (D)-(III)

Each named reaction converts different functional groups into aldehydes.

Stephen Reaction

In the Stephen reaction, nitriles (RCN) are reduced using SnCl₂ and HCl to form an iminium salt, which on hydrolysis produces an aldehyde.

Reaction:

RCN → SnCl₂+ HCl → RCH=NH → (H₃O⁺) → RCHO

Thus, Stephen reaction corresponds to reaction (II).

Gatterman-Koch Reaction

This reaction introduces a formyl group (–CHO) into an aromatic ring.

Benzene reacts with CO and HCl in the presence of AlCl₃ and CuCl catalyst to produce benzaldehyde.

Thus, Gatterman-Koch reaction corresponds to reaction (I).

Etard Reaction

In the Etard reaction, toluene is oxidized using chromyl chloride (CrO₂Cl₂) in CS₂to produce benzaldehyde after hydrolysis.

Thus, Etard reaction corresponds to reaction (IV).

Rosenmund Reduction

In Rosenmund reduction, acid chlorides are selectively reduced to aldehydes using H₂ in the presence of Pd/BaSO₄ (poisoned palladium catalyst).

Example:

Benzoyl chloride → Benzaldehyde

Thus, Rosenmund reduction corresponds to reaction (III).