Aldehydes and Ketones
Reactions with nucleophiles
Example: acetal formation of benzaldehyde with methanol, acid catalyzed.
The reaction starts with protonation of the carbonyl oxygen, followed by
attack of methanol. After a proton shift and expulsion of water a (stabilized)
carbocation is formed, which is in turn attacked by methanol.
The whole process is reversible, and steared by excess methanol or water
respectively. The comment in the window below consists of two parts: the first
line refers to the forward reaction, while on the second line the description
of the reverse reaction, the hydrolysis of the acetal, is printed.
