Match List-I with List-II
|
List-I Name Reaction |
List-II Reaction |
|
(A) Stephen Reaction |
(I) |
|
(B) Gatterman-Koch Reaction |
(II) |
|
(C) Etard Reaction |
(III) |
|
(D) Rosenmund reduction |
(IV) |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → (A)-(II), (B)-(I), (C)-(IV), (D)-(III)
All four named reactions make aldehydes, each from a different starting material: Stephen from a nitrile, Gatterman-Koch from benzene, Etard from toluene and Rosenmund from an acid chloride. The starting material and the reagent in each scheme identify the reaction.
(A) Stephen Reaction — This matches (II). A nitrile is reduced by stannous chloride and HCl to an imine, which is hydrolysed to the aldehyde.
\( \displaystyle \ce{RCN + SnCl2 + HCl -> RCH=NH} \xrightarrow{\ce{H3O+}} \ce{RCHO} \)
(B) Gatterman-Koch Reaction — This matches (I). Benzene is treated with carbon monoxide and HCl in the presence of anhydrous aluminium chloride and cuprous chloride, giving benzaldehyde.
\( \displaystyle \ce{C6H6} \xrightarrow[\text{anhyd. }\ce{AlCl3/CuCl}]{\ce{CO, HCl}} \ce{C6H5CHO} \)
(C) Etard Reaction — This matches (IV). Chromyl chloride in \( \ce{CS2} \) oxidises the methyl group of toluene to a chromium complex, which on hydrolysis gives benzaldehyde.
\( \displaystyle \ce{C6H5CH3 + CrO2Cl2} \xrightarrow{\ce{CS2}} \ce{C6H5CH(OCrOHCl2)2} \xrightarrow{\ce{H3O+}} \ce{C6H5CHO} \)
(D) Rosenmund reduction — This matches (III). Benzoyl chloride is hydrogenated over palladium on barium sulphate; the poisoned catalyst stops the reduction at the aldehyde.
\( \displaystyle \ce{C6H5COCl + H2} \xrightarrow{\ce{Pd-BaSO4}} \ce{C6H5CHO + HCl} \)
Shortcut: (A)-(II) appears only in Options (1) and (3), and of these only Option (1) has (C)-(IV).