(a) Write a curved-arrow mechanism for the hydroxide-catalyzed hydration of acetaldehyde.

(b) Write a curved-arrow mechanism for the decomposition of acetone cyanohydrin (Eq. 19.15) in aqueous hydroxide. Explain why the ketone–cyanohydrin equilibrium favors the ketone at high pH.

Transcribed Image Text:

H3C C CH3 + H-C=N acetone pH 9-10 OH H3C C CH3 C=N acetone cyanohydrin (77-78% yield) (19.15)