Organic Chemistry Chapter 7: Aldehydes and ketones II

Question 1

Alpha carbon

Answer 1

carbon adjacent to the carbonyl carbon

Question 2

Alpha hydrogens

Answer 2

hydrogens attached to the alpha carbon

Question 3

Are alpha hydrogens acidic?

Answer 3

yes – can be removed by a strong base

Question 4

What stabilizes the enolate?

Answer 4

resonance with the carbonyl

Question 5

Why are ketones less reactive?

Answer 5

Steric hindrance and alpha-carbanion destabilization

Question 6

What are the two forms that aldehydes and ketones exist in?

Answer 6

keto forms and enol forms

Question 7

Tautomers

Answer 7

isomers that can be interconverted by moving a hydrogen and a double bond. The keto and the enol are tautomers to each other.

Question 8

Michael addition

Answer 8

an enolate attacks an alpha-beta-unsaturated carbonyl creating a bond.

Question 9

Kinetic enolate

Answer 9

favored by fast, irreversible reactions at higher temperatures with weaker, smaller, bases.

Question 10

Enamines

Answer 10

tautomers of imines

Question 11

Aldol condensation

Answer 11

the aldehyde or ketone acts as both nucleophilic and electrophilic, resulting in an aldol

Question 12

Aldol

Answer 12

contains both aldehyde and alcohol functional groups

Question 13

Retro-aldol reactions

Answer 13

The reverse of aldol condensations, catalyzed by heat and base, bond between alpha and beta carbon is cleaved