In the reaction of Acetaldehyde with HCN, why is the CN(-) added first and not the H(+) ion. The mechanism is NUCLEOPHILIC ADDITION, but otherwise what could be the reasons.

My textbook didnt mention any reason aside being a Nucleophilic addition and hence the Nucleophile [CN(-)] is added first

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  • $\begingroup$ This is certainly a nucleophilic addition into a carbonyl, but whether or not the aldehyde is first activated by protonation does not change the underlying class of reaction mechanism. The book likely has discussion on why carbonyls are electrophilic and species like cyanide ion are nucleophilic. $\endgroup$
    – Zhe
    Commented Jun 10 at 19:27


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