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  2. Dieckmann condensation - Wikipedia

    en.wikipedia.org/wiki/Dieckmann_condensation

    The Dieckmann condensation is the intramolecular chemical reaction of diesters with base to give β-keto esters. [1] It is named after the German chemist Walter Dieckmann (1869–1925). [2] [3] The equivalent intermolecular reaction is the Claisen condensation. Dieckmann condensations are highly effective routes to 5-, 6-, and 7-member rings ...

  3. Thorpe reaction - Wikipedia

    en.wikipedia.org/wiki/Thorpe_reaction

    The Thorpe reaction is a chemical reaction described as a self-condensation of aliphatic nitriles catalyzed by base to form enamines. [1] [2] [3] The reaction was discovered by Jocelyn Field Thorpe. The Thorpe reaction

  4. Robinson annulation - Wikipedia

    en.wikipedia.org/wiki/Robinson_annulation

    The reaction sequence in the related Hauser annulation is a Michael addition followed by a Dieckmann condensation and finally an elimination. The Dieckmann condensation is a similar ring closing intramolecular chemical reaction of diesters with base to give β-ketoesters. The Hauser donor is an aromatic sulfone or methylene sulfoxide with a ...

  5. Claisen condensation - Wikipedia

    en.wikipedia.org/wiki/Claisen_condensation

    The Dieckmann condensation, where a molecule with two ester groups reacts intramolecularly, forming a cyclic β-keto ester. In this case, the ring formed must not be strained, usually a 5- or 6-membered chain or ring. Retro-Claisen condensation is the reverse of the title reaction, i.e., the base-induced cleavage of 2-ketoesters

  6. Dowd–Beckwith ring-expansion reaction - Wikipedia

    en.wikipedia.org/wiki/Dowd–Beckwith_ring...

    The cyclic β-keto ester can be obtained through a Dieckmann condensation. The original reaction consisted of a nucleophilic aliphatic substitution of the enolate of ethyl cyclohexanone-2-carboxylate with 1,4-diiodobutane and sodium hydride followed by ring expansion to ethyl cyclodecanone-6-carboxylate.

  7. Acyloin condensation - Wikipedia

    en.wikipedia.org/wiki/Acyloin_condensation

    Acyloin condensation is a reductive coupling of two carboxylic esters using impure metallic sodium to yield an α-hydroxyketone, also known as an acyloin. [1] [2] [3] The acyloin condensation. The reaction is most successful when R is aliphatic and saturated, and typically performed with a silyl chloride reactant to trap the product as a ...

  8. Ring forming reaction - Wikipedia

    en.wikipedia.org/wiki/Ring_forming_reaction

    A ring forming reaction or ring-closing reaction in organic chemistry is an umbrella term for a variety of reactions that introduce one or more rings into a molecule. A heterocycle forming reaction is a reaction that introduces a new heterocycle.

  9. Walter Dieckmann - Wikipedia

    en.wikipedia.org/wiki/Walter_Dieckmann

    Walter Dieckmann (8 October 1869 – 12 January 1925) was a German chemist. He is the namesake of the Dieckmann condensation, the intramolecular reaction of diesters with base to give β-keto esters. Dieckmann studied at the University of Munich and became assistant of Adolf von Baeyer