# What is a stepwise mechanism for the hydroxide ion base catalyzed tautomerization of acetone to the enol form?

Sep 22, 2016

${H}_{3} C - C \left(= O\right) C {H}_{3} + H {O}^{-} r i g h t \le f t h a r p \infty n s {H}_{2} C = C \left({O}^{-}\right) \left(N {a}^{+}\right) C {H}_{3}$

#### Explanation:

Acetones can form equilibrium quantities of the enol:

${H}_{3} C - C \left(= O\right) C {H}_{3} r i g h t \le f t h a r p \infty n s {H}_{2} C = C \left(- O H\right) C {H}_{3}$

Of course, the equilibrium lies to the left as written, but given a strong base, the enolic hydrogen may be deporotonated to form the enolate:

H_2C=C(-OH)CH_3 + ""^(-)OH rarr H_2C=C(-O^-)CH_3 + H_2O

The enolate is itself in equilibrium with the carbanion:

${H}_{2} C = C \left(- {O}^{-}\right) C {H}_{3} \rightarrow {H}_{2}^{-} C - C \left(= O\right) C {H}_{3}$

And the carbanion is used to make $C - C$ bonds.