A variation of the Claisen condensation, the Dieckmann condensation, where a molecule with two ester groups reacts intramolecularly, forming a cyclic ?-keto ester. In this case, the ring formed must not be strained, usually a 5- or 6-membered ring.

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A variation of the Claisen condensation, the Dieckmann condensation, where a molecule with two ester groups reacts intramolecularly, forming a cyclic ?-keto ester. In this case, the ring formed must not be strained, usually a 5- or 6-membered ring.