Aldehydes and ketones (sections I and II)

Question 1

In the presence of water, aldehydes and ketones form ______

Answer 1

Geminal diols

(two alcohols that are on the same carbon)

Question 2

A Nitrogen based functional group can react with a carbonyl to form ____

Answer 2

Imines

Question 3

Imines can be tauteromized to form ______

Answer 3

Enamines

A double bond where one of the R groups is a nitrogen based functional group

Question 4

Reacting HCN with carbonyls results in ____

Answer 4

Cyanohydrins

(Has a CN group and OH group)

Question 5

Why are aldehydes more reactive than ketones?

Answer 5

The aldehydes experience less steric hinderance

Question 6

What is the difference between a keto and an enol?

Answer 6

A keto has a carbonyl (think keto like ketone)

An enol has an alcohol (ends in -ol like alcohol), and the double bond comes off the carbon attached to alcohol

Question 7

Why is the thermodynamic enolate more stable than then kinetic enolate?

Answer 7

The thermodynamic enolate has the double bond at the most substituted carbon while the kinetic enolate has the double bond at the less substituted carbon

Question 8

Which is more stable: the keto or the enol?

Answer 8

The enol because the double bond next to the alcohol allows for resonance stabilization

Question 9

Describe an aldol condensation, including what two species react, what the intermediate is, and what the final product looks like

Answer 9

An aldol condensation is a nucleophilic addition to a carbonyl
-Ketones or aldehydes react with an enol or enolate ion
-The intermediate is a compound that had an aldehyde (or at least a carbonyl) and an alcohol
-The final product is a carbonyl with a conjugated double bond