Tautomerization is a chemical reaction that describes the transfer of a hydrogen atom and a double bond within a molecule, resulting in the conversion of one isomer (tautomer) into another. This process is particularly common between keto and enol tautomers where the hydrogen atom moves from an oxygen (in the case of ketones and aldehydes) to a carbon atom, generating an enol (a compound with a vinyl alcohol moiety).
Tautomerization is important in organic chemistry because it significantly influences the reactivity and stability of compounds, affects biochemical processes such as base pairing in DNA, and plays a crucial role in the mechanisms of certain organic reactions like enolization, which is key for the formation of carbon-carbon bonds in aldol reactions.