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Can this be classified as nucleophilic substitution?

IMG_20160612_132958.jpgThis is the second step of making a hydroxynitrile from a ketone. As i observe it the hydroxy nitrile intermediate is a nucleophile attacking HCN and gets substituted in place of CN- . am i right in saying just this second step ...is a nucleophilic substitution?

The entire mechanism is considered nucleophilic addition- because combining both steps, the entire hcn is added to the ketone. Is this a right way to look at it?
(edited 7 years ago)
Original post by chhhhelsie
IMG_20160612_132958.jpgThis is the second step of making a hydroxynitrile from a ketone. As i observe it the hydroxy nitrile intermediate is a nucleophile attacking HCN and gets substituted in place of CN- . am i right in saying just this second step ...is a nucleophilic substitution?

The entire mechanism is considered nucleophilic addition- because combining both steps, the entire hcn is added to the ketone. Is this a right way to look at it?


Would tend to say this is not a nucleophilic substitution. If it is, the partial oxygen-anion of the ketone would get away from. This is not the case. Instead of splitting from ketone, the partial oxygen-anion reacts with the partial hydrogen-cation (proton) of HCN. It looks like that the partial H-cation is added to the ketone to form the functional group OH. And thus it looks rather like a nucleophilic addition than a substitution in my view.

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