Topic 4: Enols and Enolates

Which one of the compounds shown is most acidic?

• ethyl acetoacetate

• 2-butanone

• ethyl pentanoate

• 1-butanol

• 3-pentanone

Which of the indicated α-hydrogens is most acidic?

• I

• II

• III

• IV

• V

Which is the most acidic hydrogen in the compound shown?

• I

• II

• III

• IV

• V

Which is the most acidic hydrogen in the compound shown?

• I

• II

• III

• IV

• V

Which is the most acidic hydrogen in the compound shown?

• I

• II

• III

• IV

• V

Which carbon atom has the most acidic hydrogen in the compound shown?

• I

• II

• III

• IV

• V

Arrange the indicated hydrogens in decreasing order (most to least) of acidity.

• I > II > III > IV

• IV > II > III > I

• III > II > I > IV

• II > I > III > IV

• III > I > II > IV

Which of the choices is a keto-enol tautomeric pair?

• I

• II

• III

• IV

• V

Which one of the compounds shown is most likely to favor the enol tautomer over the ketone tautomer?

• I

• II

• III

• IV

• V

Explain why the equilibrium shown favors the enol tautomer.

• The enol tautomer is stabilized by the intramolecular hydrogen bonding.

• The enol tautomer is stabilized by the conjugated π system of the aromatic system.

• The enol tautomer is stabilized by lacking a conjugated π system.

• A and B

• A and C