Alder-Rickert reaction

It seems accepted that almost any "retro-Diels-Alder" reaction can be included in the grouping, "Alder-Rickert Reaction". 

The Alder-Rickert reaction can be employed in the preparation of 3-substituted furans88 ... 

Clauson-Kaas337 worked out a vitamin B6 synthesis on the basis of this method. Furan is converted by an Alder-Rickert reaction into furan-3,4-dicarboxylic ester, which is in turn converted into pyri-doxine, according to the following scheme ... 

The retro-Diels-Alder reaction (or Alder-Rickert reaction) was used in the first synthesis of a cycloproparene, namely l//-cyclopropabenzene (3). In this method, the Diels-AIder adduct 2 of dimethyl butynedioate with 1,6-methanocyclodecapentaene (1) was subjected to pyrolysis at 400 C and 1 Torr. This led to elimination of dimethyl phthalate (4) and formation of the product cycloproparene in 45% yield. 

Furans react with electron-deficient alkynes giving 7-oxabicyclo[2.2.1]heptadienes (30). Whereas it is possible to induce thermally a retro cycloaddition <62ioc3520.89CC1238>, normally these intermediates are reduced at the less hindered side, yielding 7-oxabicyclo[2.2.1]heptenes (31) (Scheme 30). Elimination of ethylene (Alder-Rickert reaction <37CB1354> yields substituted furans (Scheme 30) <6814501, 85JHC1233, 87BSF131>. 

This reaction was first reported by Alder and Rickert in 1936. It is the extension of the Diels-Alder Reaction in which the Diels-Alder cycloadducts extrude the cleavable groups to give even more stable aromatic compounds under thermal conditions or in the presence of either acid or base. Thus this reaction is generally known as the Alder-Rickert reaction. In addition, the Diels-Alder cycloadducts can also be converted into aromatic compounds via rearrangement or oxidation. ... 

Shown here is a typical Alder-Rickert reaction in which Ri and R2 are eliminated. Other groups are also possible to cleave. 

Other references related to the Alder-Rickert reaction are cited in the literature. 

Alder-Rickert cleavage was also examined as a potential route for 100 and 102, but the required precursors could not be synthesized. Bis-methano[14]annulene 105 added dicyanoacetylene in the wrong sense, and did not yield 106, which could have served as precursor of 102. Similarly, the attempted Diels-Alder reaction of the bridged cyclopropafl OJannulene 107 with dlmethoxycarbonylacetylene, which should furnish 108, produced only decomposed material. This is consistent with the observation of Halton and Russel that 107 does not add to 4-phenyl-1,2,4-tria-zoline-3,5-dione. In order to circumvent the low reactivity of 107 in cycloaddi-... 

Other approaches to alkylidenecycloproparenes have been attempted without success. Aromatization of appropriate alkylidenecyclopropanes or their precursors could not be realized, and flash vacuum pyrolysis of methylene phthalide and 3-methylene-2-coumaranone afforded rearrangement products rather than alkylidenecycloproparenes via extrusion of 002. The photochemical or thermal decomposition of the sodium salt of benzocyclobutenone p-toluenesulfonyl hydrazone led to products derived from dimerization of the intermediate benzocy-clobutenylidene, or from its reaction with the solvent, but no ring-contracted products were observed. When the adduct of methylene-l,6-methano[10]annulene to dicyanoacetylene (249) was subjected to Alder-Rickert cleavage, phenylacety-lene (250) was formed, which derives reasonably from the parent 234. ... 

It had previously been shown that 2,4,6-triphenyl-l,3-azaarsenin 36 could be converted to highly substituted arsenins 38 via a reaction with dienophiles followed by Alder-Rickert cleavage of the intermediate adduct as illustrated in... 

A variety of diverse synthetic methods have been empioyed for the preparation of cyclopropane (1 j. Schlatter and Demjanov and Dojarenko pyrolyzed cyclopropyltrimethylammonium hydroxide at 320°C using platinized asbestos as the catalyst. About equal amounts of cyclopropene (1) and cyclopropyidimethylamine are formed, contaminated with some dimethyl ether and ethylene. Treatment with dilute hydrochloric acid removed the amine from the gas stream and 1 was separated from the other products by gas chromatography. Alder-Rickert cleavage of the Diels-Alder adduct formed from cycloheptatriene and dimethyl acetylenedicarboxylate resulted only in the formation of a polymer and trace amounts of 1. A simple approach by Closs and Krantz based on the synthesis of 1-methylcyclopropene involved the addition of allyl chioride to a suspension of sodium amide in mineral oil at 80°C. Under the conditions employed, 1 could readily escape from the reaction mixture. Though a number of variations were tried, the yield of 1 never exceeded 10%. 

Oxidation of one molar proportion with sodium pieriodate produces two equivalents of formic acid, in accordance with the existence of hydroxyl groups attached to four contiguous carbon atoms. This oxidation (and also that carried out with lead tetraacetate) gives an aldehyde, whose semicar-bazone has an analysis corresponding to that of the semicarbazone of an ethyl formyl-methyl-furoate (XII). By oxidation of aldehyde XII with silver oxide in alkaline solution, 2-methyl-3,4-furandicarboxylic acid (XIV) was obtained this was identical with the compound described by Alder and Rickert.20 The identity was confirmed by preparation of the respective dianilides. The acid XIV has also been prepared by the reaction between the sodium salt of ethyl acetoacetate and ethyl bromopyruvate.9... 

The synthetic breakthrough in cycloproparene chemistry was achieved by Anet and Anet in 1964 who prqtared l,l-dimethyl-3-methoxycarbonylbenzocyclo-propene (9) by irradiation of the substituted 3H-indazole 8. The parent benzocyclopropene (1) was obtained a year later by Vogel et al. by retro-Diels-Alder reaction (Aldw-Rickert cleavage) of 10. ... 

AJder-Rickert Cycioaddition J Diels-Alder Reaction J Diels-Alder Reaction 0 Intermolecular I j Intramolecular... 

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