Chapter 22: Enols and Enolates

Question 1

alpha protons

Answer 1

• protons on carbons directly attached to carbonyl carbon
• alpha protons are acidic
  
  • removal of alpha proton generates an anion that is fairly reactive

Question 2

Compounds that differ by the placement of just one proton are called ___.

Answer 2

• tautomers

Question 3

Answer 3

Question 4

Answer 4

Question 5

In Keto-Enol tautomerization, equilibrium favors the ____ form

Answer 5

• ketone form, becuase carbonyl formation is driving force

Question 6

Ketones can be converted to Enols and vice-versa via which methods?

Answer 6

• acid or base catalyzed methods

Question 7

Acid catalyzed keto-enol tautomerization

Answer 7

• protonate with H3O+
• deprotonate with H2O
• enolate intermediate

Question 8

Base-catalyzed keto-enol tautomerization

Answer 8

• protonate with H2O
• deprotonate with -OH
• enolate interediate

Question 9

Enols as nucleophiles

Answer 9

• only occurs with ketones that are able to tautomerize to enol

Question 11

Forming alpha-halo ketones

Answer 11

Question 12

Forming alpha-halo ketones:

Answer 12

Question 13

Hell-Volhard-Zelinsky Reaction:

Answer 13

-used to halogenate COOHs

Question 14

Making enolates:

Answer 14

Question 15

Alkylation of Enolates

Answer 15

Question 16

Alylation of assymetrical enolates: This is the ____ product

Answer 16

• Thermodynamic product

Question 17

Alkylation of assymetrical enolates: this is the ____ product

Answer 17

• kinetic

Question 18

Aldol addition:

Answer 18

Question 19

Aldol condensation:

Answer 19

• creates alpha-beta unsaturated ketones

Question 20

If using two ketones in aldol addition, you need to make sure that one ketone has no ____, to prevent crossed-aldol reactions

Answer 20

alpha protons

Question 21

Claisen Condensation

Answer 21

• When ester enolates attack esters
• note: the alkoxide used much match the ester

Question 22

Decarboxylation

Question 23

Acetoacetic Ester Synthesis

Answer 23

• makes ketones

Question 24

Malonic Ester Synthesis

Answer 24