Organic Test Question

Answer the 4 Parts to: Aldol Reaction

Use this picture of Aldol Reaction of Cyclopentanone to answer questions 1 and 2

1.      During step 3, what type of overall reaction occurs in the Aldol reaction?

(A) Acid Catalysed dehydration

(B) Acid Catalysed Aldol addition

(C) Electrophilic addition

(D) Acid catalysed enolization

Answer: (A) Acid Catalysed dehydration

2.      Which functional group is responsible for the formation of the stable conjugated enone?

Water

Hydroxy group

Acid catalyst

Carbonyl group

Answer: (D) Carbonyl group

True or False: Explain

3.      In the presence of hydroxide, either propanal or acetaldehyde serve as a nucleophile in an aldol reaction.

Answer True

4.      Either propanal or acetaldehyde can serve as an electrophile in an aldol reaction.

Answer: True

In the presence of hydroxide, each aldehyde can enolize to form a nucleophilic enolate anion. The enolate can react with an unionized aldehyde in the first step of an aldol condensation. The unionized aldehyde is an electrophile in this reaction.