Organic Chemistry Multiple Choice Questions on “Intramolecular Claisen Condensation”.
1. Which type of precursor is used as reactant in intramolecular Claisen condensation?
a) One molecule with an ester end
b) Two molecules of ester
c) One molecule with two ester ends
d) One molecule of ester and enolate
Answer: c
Clarification: In intramolecular Claisen condensations, reactions occur for 1,6 and 1,7 diesters, as these substances result in the formation of compounds containing five and six membered rings, respectively.
2. Which is the main product of the following reaction?
a) 
b) 
c) 
d) 
Answer: a
Clarification: This is an example of an intramolecular Claisen condensation. These reactions occur for 1,6 and 1,7 diesters, as these substances result in the formation of compounds containing five and six membered rings, respectively.
3. What is the other name for the intramolecular Claisen condensation?
a) Perkin condensation
b) Stobbe condensation
c) Knoevenagel condensation
d) Dieckmann condensation
Answer: d
Clarification: Diester compounds can be used to give an intramolecular Claisen condensation which is known as the Dieckmann condensation.
4. Dieckmann Condensation is intramolecular condensation of ______________ to form cyclic product.
a) diamide
b) diol
c) diester
d) diketone
Answer: c
Clarification: These reactions occur for 1,6 and 1,7 diesters, as these substances result in the formation of compounds containing five and six membered rings.
5. What will be the product of the following intramolecular Claisen condensation?
a)
b)
c)
d)
Answer: c
Clarification: Favours the formation of the more stable 5- or 6-membered rings, as the ring stain in 5 and 6 membered rings are less.
6. Which is the main product of the following intramolecular Claisen condensation?
a)
b)
c)
d) 
Answer: d
Clarification: This reaction is an intramolecular Claisen condensation, which is followed by attack of carbocation on carbon attached to ester group.
