. In which of the following substrate, rate of Benzoin condensation will be maximum:

Best Answer

(a)

Benzoin condensation is due to stability of intermediate (III) when negative charge on C is extensively delocalized in benzene ring, Nitro and group. In all other cases, such dispersal is not extensively possible. On the other hand – NO₂ is also creating positive charge centre on carbonyl carbon, making it more susceptible to nucleophilic attack of CN^–. Hence, A. is the correct option.