Type of functional isomerism in which the isomers are in dynamic equilibrium with each other. commonly they are also called as Keto or Enol form

keto= ketone group
enol= alcohol group

So the process in which keto form is converted to enol form is said to be Tautomerization. this interconversion takes place by the movement of hydrogen.

1. Acetone Tautomerization

2. Tautomerization in Lactam-Lactim

Explanation:

When writing the resonance structures of a compound. It was observed that the relative position of atomic nuclei remained unchanged. The structures which differ in the relative position of their atoms are not resonance form but different compounds which are isomeric with each other and are capable independent existence. The most common example of Tautomerism are provided buy carbonyl compounds containing alpha-hydrogen, in which the proton (hydrogen) from alpha-carbon shifts to carbonyl oxygen, associated with appropriate movement of electron pair form an ENOL , this process is called ENOLIZATION. The hydrogen then moves back to convert the enol form to keto form.





Keto form is therefore more stable by 69kj/mol.