UPSC Combined Geo-Scientist, Mains · 2025 · Mains Paper III
Q7(c)(i). 4-Methoxybenzaldehyde with NaCN: benzoin condensation
Question
Predict the product and give mechanism for the formation of the same in the reaction given below: [4-methoxybenzaldehyde, NaCN, C₂H₅OH, H₂O → ?; scheme given in the paper]
Answer in brief
Benzoin condensation. Product: 4,4′-dimethoxybenzoin (anisoin), 2-hydroxy-1,2-bis(4-methoxyphenyl)ethan-1-one.
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Coversbenzoin condensationanisoincyanide catalysisumpolungacyl anion equivalent
All parts of Question 7
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- 7(b)(ii) Furil to furilic acid: benzilic acid rearrangement5 marks
- 7(c)(i) 4-Methoxybenzaldehyde with NaCN: benzoin condensation5 marks
- 7(c)(ii) Norrish Type II against Type I in two ketones5 marks