A-LevelChemistryCarbonyl compounds9701/12 · Oct/Nov 2015 · Q271 Mark

What is the mechanism for the reaction of ethanal, CH3CHO, with hydrogen cyanide, HCN, in the presence of a base?

This question uses a diagram from the original paper, which isn't shown here. Open the full paper from the past papers archive to see it.

A[Diagram of mechanism A, showing protonation by H-]

B[Diagram of mechanism B, showing nucleophilic addition of cyanide and protonation by HCN]

C[Diagram of mechanism C, showing initial protonation then cyanide attack]

D[Diagram of mechanism D, showing a free radical mechanism]

✓ Correct answer

B: [Diagram of mechanism B, showing nucleophilic addition of cyanide and protonation by HCN]

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Topic: Carbonyl compounds, A-Level Chemistry (syllabus 9701). Multiple choice, 1 mark.
Source: A-Level Chemistry, Oct/Nov 2015 Paper 1 Variant 2, question 27.

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