Dieckmann reaction

Esters of dicarboxyUc acids having hydrogen on tbe 8 or e carbon atoms undergo intramolecular cyclisation when heated with sodium or with sodium ethoxide. This cyclisation is known as the Dieckmann reaction. It is essentially an application of the Claiseu (or acetoacetic eater) condensation to the formation of a ring system the condensation occurs internally to produce s... 

Benzilic acid rearrangement Benzoin reaction (condensation) Blanc chloromethylation reaction Bouveault-Blanc reduction Bucherer hydantoin synthesis Bucherer reaction Cannizzaro reaction Claisen aldoi condensation Claisen condensation Claisen-Schmidt reaction. Clemmensen reduction Darzens glycidic ester condensation Diazoamino-aminoazo rearrangement Dieckmann reaction Diels-Alder reaction Doebner reaction Erlenmeyer azlactone synthesis Fischer indole synthesis Fischer-Speior esterification Friedel-Crafts reaction... 

Synthesis This cyclisation version of the Claisen ester condensation is sometimes called the Dieckmann Reaction. 

Dieckmann reaction (Section 21 2) An intramolecular version of the Claisen condensation... 

Dieckmann reaction, 4, 471 Indolizidine alkaloids mass spectra, 4, 444 Indolizidine immonium salts reactions, 4, 462 Indolizi dines basicity, 4, 461 circular dichroism, 4, 450 dipole moments, 4, 450 IR spectra, 4, 449 reactivity, 4, 461 reviews, 4, 444 stereochemistry, 4, 444 synthesis, 4, 471-476 Indolizine, 1-acetoxy-synthesis, 4, 466 Indolizine, 8-acetoxy-hydrolysis, 4, 452 synthesis, 4, 466 Indolizine, I-acetyl-2-methyI-iodination, 4, 457 Indolizine, 3-acyloxy-cyclazine synthesis from, 4, 460 Indolizine, alkyl-UV spectra, 4, 449 Indolizine, amino-instability, 4, 455 synthesis, 4, 121 tautomerism, 4, 200, 452 Indolizine, 1-amino-tautomerism, 4, 38 Indolizine, 3-amino-synthesis, 4, 461, 470... 

The carbon-car bon bond-fonrring potential inherent in the Claisen and Dieckmann reactions has been extensively exploited in organic synthesis. Subsequent transfonnations of the p-keto ester products permit the synthesis of other functional groups. One of these transformations converts p-keto esters to ketones it is based on the fact that p-keto acids (not esters ) undergo decarboxylation readily (Section 19.17). Indeed, p-keto acids, and their- conesponding carboxylate anions as well, lose carbon dioxide so easily that they tend to decarboxylate under the conditions of their formation. 

Oxaestrone has been synthesised from 7-methoxychroman-4-one <96JCS(P1)841>. Formation of the complex chroman-3-one (16) by a Dieckmann reaction and its conversion to the 4-diazo derivative are signifcant steps in the synthesis of the pentacyclic system (17) <96TL5243>. 

We have already discussed a large group of reactions in which carbanions add to the C=0 group (cf. pp. 221-234), including examples of intramolecular carbanion addition, e.g. an aldol reaction (p. 226), Dieckmann reaction (p. 230), and the benzilic acid rearrangement (p. 232), and also to the C=C—C=O system, the Michael reaction... 

The same paper reports another route to 11-membered acetylenic lactones via an intramolecular retro-Dieckmann reaction (equation I). Thus treatment of 3 with... 

Should there be two ester functions in the same molecule, then it is possible to achieve an intramolecular Claisen reaction, particularly if this results in a favourable five- or six-membered ring. This reaction is usually given a separate name, a Dieckmann reaction, but should be thought of as merely an intramolecular extension of the... 

The reverse Claisen reaction is common, especially with cyclic P-ketoesters, such as one gets from the Dieckmann reaction (see Section 10.8). If one only wants to hydrolyse the ester, it thus becomes necessary to use the rather less effective acid-catalysed hydrolysis method (see Section 7.9.2). 

Spatz JH, Welsch S J, Duhaut DE, lager N, Boursier T, Fredrich M, Allmendinger L, Ross G, Kolb J, Burdack C et al (2009) Tetramic acid derivatives via Ugi-Dieckmann-reaction. Tetrahedron Lett 50 1705-1707... 

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