How Carbonyls Gain Halogens at the α-Carbon

Base-promoted α-halogenation of aldehydes and ketones is a reaction that replaces α hydrogens with halogens. The α carbon is the carbon next to the carbonyl group. A base starts the process by removing an α hydrogen and forming a nucleophilic enolate ion.

The enolate then reacts with the halogen ...

Aldehydes and ketones undergo α-halogenation in the presence of a full equivalent of base and halogen.

This reaction proceeds via the base-catalyzed deprotonation of α hydrogen to form a nucleophilic enolate intermediate, which then reacts with halogen to give α-halogenated carbonyl compound.

The presence of halogen in the resultin...