A β-ɣ-unsaturated carbonyl compound rearranges to a more stable conjugated ⍺,β-unsaturated compound in the presence of either acid or base. b. Propose a mechanism for the acid-catalyzed rearrangement.

Which of the following represents the enol form of ${\mathrm{CH}}_3\mathrm{COCH}{3}_{}$ (acetone)?

Draw the enol tautomer for cyclopentanone

Which of the following pairs are keto–enol tautomers?

d.

e.

Using cyclopentanone as the reactant, show the product of a. acid-catalyzed keto–enol interconversion.

Draw the enol tautomers for each of the following compounds. For compounds that have more than one enol tautomer, indicate the one that is more stable.

f.

Show each step in the mechanism of the acid-catalyzed interconversion of (R)- and (S)-3-methylpentan-2-one.

Draw a structure for each of the following: d. the enol tautomer of cyclopentanone