Darzens glycidate condensation

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Georges Darzens (1867–1954)

The Darzens glycidate condensation is a name reaction in organic chemistry and named after its discoverer, the French chemist Georges Darzens (1867–1954). The reaction is a method for chain extension of aldehydes or ketones with α-chlorocarboxylic acid esters via oxirane carboxylic acid esters.

Reaction scheme for the Darzens glycidate condensation

mechanism

The α-halogen ester 1 is deprotonated and condensed with an aldehyde or a ketone to form an α, β-epoxycarboxylic acid ester 4 . This ester is saponified to form compound 7 and then protonated. After decarboxylation , an aldehyde (R 2 = H) or ketone (R 2 = alkyl, aryl) 10 is formed .

Mechanism of the Darzens glycidate condensation

Individual evidence

  1. ^ Georges Darzens: Méthode générale de synthèse des aldéhydes à l'aide des acidic glycidiques substité . In: Comptes rendus hebdomadaires des séances de l'Académie des sciences . tape 139 , 1904, pp. 1214–1217 ( digitized on Gallica ).
  2. Georges Darzens: Méthode générale de synthèse d'éthers glycidiques ab substités et de cétones . In: Comptes rendus hebdomadaires des séances de l'Académie des sciences . tape 141 , 1905, pp. 766 ( digitized on Gallica ).
  3. Georges Darzens: Condensation glycidique des aldéhydes avec l'éther a-chloropropionique . In: Comptes rendus hebdomadaires des séances de l'Académie des sciences . tape 142 , 1906, pp. 214–215 ( digitized on Gallica ).
  4. ^ T. Laue, A. Plagens: Name and keyword reactions of organic chemistry . 5th edition, Teubner Studienbücher Chemie, 2006, ISBN 3-8351-0091-2 , p. 91.