Enolate Chemistry

Question 1

Enolates

Answer 1

Carboxylic acids, esters, amides

Question 2

Tautomers

Answer 2

structures formed by breaking/forming new bonds

Question 3

Enol

Answer 3

a functional group with double bond and OH group

Question 4

Tautomerism

Answer 4

-will only work if there is one acidic hydrogen and can be removed by a base- a H bound to alpha carbon (which is the carbon next to the carbonyl carbon)

Question 5

Acid-catalyzed Keto-Enol Tautomerism

Answer 5

Step one: add a strong acid to protonate carbonyl oxygen
Step 2: water= weak base and removes one of the alpha hydrogens. double bond forms between alpha carbon and carbonyl carbon and pushes charge up to the oxygen to get rid of the positive charge

Question 6

Base-catalyzed Keto-enol Tautomerism

Answer 6

Step one: add strong base to acetone to attacks alpha hydrogen and forms the double bond between the alpha carbon and carbonyl carbon this puts neg charge on oxygen
Step two: water (which is the OH protonated from NaOH) comes in and the O- becomes OH

Question 7

Enol stability

Answer 7

1. resonance

2. hydrogen bonding

Question 8

Asymmetric ketones

Answer 8

double bond can go several places, but some are favored

Question 9

Kinetic favored

Answer 9

formed quickly, but less stable. double bond on less substituted. low temperature formed, strong & bulky base

Question 10

Thermodynamic

Answer 10

Double bond forms between carbonyl carbon and substituted carbon. High temperature, less quick, more stable. weaker and less bulky base

Question 11

Adol condensation

Answer 11

aldehyde or ketone condense to form adol

Question 12

Base-catalyzed with aldehyde

Answer 12

strong base removes alpha hydrogen to form enolate. A new carbon carbon bond is formed and oxygen is protonated. possible to remove alpha hydrogen to get a double bond and we get alpha beta unsaturated aldehyde (dehydration reaction)

Question 13

Acid-catalyzed

Answer 13

enol is protonated and can attack carbonyl carbon of aldehyde to get aldol. can break down to the unsaturated

Question 14

Symmetrical ketone

Answer 14

either the catalyzed product or the dehydrated product

Question 15

Asymmetric ketone

Answer 15

can generate two different enolates if there are two alpha carbons. after dehydration, all together 4 different products

Question 16

Cross aldol condensation

Answer 16

-can produce too many products

when chemists do this, they begin with one ketone (make sure only one alpha carbon has hydrogens)

Question 17

Enolates act as…

Answer 17

neucleophiles

Question 18

Carbonyl carbons act as ….

Answer 18

electrophiles

Question 19

Michael addition

Answer 19

Enolate attacks the beta carbon (can act as electrophile) of the alpha beta unsaturated aldehyde or ketone
double carbon carbon bond removed and neg charge on carbonyl carbon
then removed to make a “1,5”

Question 20

Robinson annulation

Answer 20

michael product and turn into enolate. forms a cyclic structure. de hydration can result in the new carbon carbon double bond to form an alpha beta unsaturated aldehyde or ketone