Write chemical reactions involved in :(a) Rosenmund reduction.(b) Gatterman Koch formylation.(c) Cannizzaro reaction of methanal.

Q.16 Write chemical reactions involved in :
(a) Rosenmund reduction.
(b) Gatterman Koch formylation.
(c) Cannizzaro reaction of methanal.

Doubtly Asked 29 Oct 2026 Board exam · March 2024 hsc 12th Save WhatsApp Report

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(a) Rosenmund reduction: an acid chloride is reduced by H₂ over Pd poisoned with BaSO₄ to an aldehyde.

C₆H₅COCl + H₂ → (Pd–BaSO₄, boiling xylene) C₆H₅CHO + HCl

(b) Gattermann–Koch formylation: benzene is treated with CO and HCl in the presence of anhydrous AlCl₃ and CuCl.

C₆H₆ + CO + HCl → (anhyd. AlCl₃/CuCl) C₆H₅CHO + HCl

(c) Cannizzaro reaction of methanal: methanal (no α-H) undergoes self oxidation-reduction with concentrated NaOH.

2HCHO + NaOH (conc.) → (Δ) CH₃OH + HCOONa

Doubtly AI · 29 Oct 2026 AI-generated · not yet verified Report

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