Question

Which type of precursor is used as reactant in intramolecular claisen condensation?

• A. One molecule with an ester end
• B. Two molecule of ester
• C. One molecule with two ester ends
• D. One molecule of ester and enolate

Answer 1

The correct option is C One molecule with two ester ends

Ester undergoes self condensation in presence of strong base to give $\beta$-ketoester. This reaction is called Claisen condensation reaction.
Dieckmann condensation is the intramolecular condensation reaction of diesters with a strong base to give $\beta$-ketoesters.
Thus, the reactant should have two ester group in the single molecule.