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CBSE Class 12 · 2022 · Aldehydes Ketones and Carboxylic AcidsShort Answer

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Explain the following reactions:
a) Clemmensen reduction
b) Stephen reaction

Answer: (a) C=O → CH₂ with Zn(Hg)/conc. HCl. (b) RCN + SnCl₂/HCl → iminium salt → H₃O⁺ → RCHO.

Solution

(a) Clemmensen: amalgamated zinc in concentrated HCl reduces a carbonyl to methylene —

(b) Stephen: partial reduction of a nitrile with SnCl/HCl, then hydrolysis, gives the aldehyde —

CBSE Class 12 Board · 2022 · Subjective

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