5344-23-0Relevant academic research and scientific papers
Propynal equivalents and diazopropyne: Synthesis of all mono-13C isotopomers
Seburg, Randal A.,Hodges, Jonathan A.,McMahon, Robert J.
experimental part, p. 1626 - 1643 (2009/10/17)
Mechanistic and spectroscopic investigations of reactive C 3H2 hydrocarbons necessitated the preparation of diazopropyne isotopomers bearing mono-13C substitution at each of the three unique positions. The diazo compounds and their tosylhydrazone precursors were prepared from the mono-13C isotopomers of propynal (in the form of either the aldehyde or the diethyl acetal). The introduction of 13C-labeling at either alkyne position in propynal utilized the Corey - Fuchs procedure for chain homologation.
Process for continuously preparing acetals of alpha, beta-dicarbonyl compounds
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Page 3, (2008/06/13)
The present invention relates to a process for preparing acetals of α,β-dicarbonyl compounds of the general formula (R″O)2CRCR′(OR″)2 which are obtained by continuous reaction of α,β-dicarbonyl compounds R—CO—CO—R′ with alcohols R″OH or HO—X—OH in countercurrent.
Glyoxal derivatives and method for making the same
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, (2008/06/13)
This invention provides glyoxal derivatives and a method for making these derivatives. A particularly useful derivative, 1-chloro-1,2,2-trialkoxyethane, and a facile method for making these alpha-halo ethers are provided. The alpha-halo ethers are valuable intermediates in the manufacture of a variety of commercial compounds.
Substrate Specificity and Carbohydrate Synthesis Using Transketolase
Kobori, Yoshihiro,Myles, David C.,Whitesides, George M.
, p. 5899 - 5907 (2007/10/02)
This paper describes the use of the enzyme transketolase as a catalyst in organic synthesis.The properties of transketolase from both yeast and spinach were investigated.The yeast enzyme was found to be more convenient for routine use.Examination of the substrate specificity of yeast tansketolase demonstrated that the enzyme accepts a wide variety of 2-hydroxy aldehydes as substrates.A practical protocol for tansketolase-catalyzed condensation of hydroxypyruvic acid with these aldehydes has been developed and used for the synthesis of four carbohydrates: L-idose, L-gulose, 2-deoxy-L-xylohexose, and L-xylose.
THE MONOACETALIZATION OF GLYOXAL: A DIRECT SYNTHESIS OF 2,2-DIMETHOXY AND DIETHOXY ETHANALS
Sangsari, Farid Hamedi,Chastrette, Francine,Chastrette, Maurice
, p. 1343 - 1348 (2007/10/02)
Direct monoacetalization of glyoxal by methanol or ethanol is described.Yields of 50 to 70percent are obtained.
Les dialkoxy-2,2 ethanals, synthons difonctionnels a deux carbones : preparation par acetalisation du glyoxal et quelques applications en synthese
Stambouli, Abdelhamid,Hamedi-Sangsari, Farid,Amouroux, Roger,Chastrette, Francine,Blanc, Alain,Mattioda, Georges
, p. 95 - 100 (2007/10/02)
Known for a long time, 2,2-dialkoxy ethanals had to be prepare by rather tedious indirect pathways since monoacetalization of glyoxal was unknown.We discovered that it is possible to acetalize only one of the glyoxal functions using a great excess of alcohol, in the presence of an active enough catalyst.With careful monitoring of the reaction, 50 to 70 percent yield of monoacetals is obtained.The monoacetal is formed much quicker than the diacetal and the maximum yield is rather quickly obtained; with further elimination of water, diacetalization proceeds at the expense of the monoacetal.Depending on azeotropic compositions and boiling points, one of the following methods is used: 1.General method: 40 percent aqueous glyoxal (1 mol), alcohol (10 mol), catalyst (0.01 to 0.1 equivalent) and solvent are refluxed with azeotropic water extraction.The monitored (GC) reaction is stopped at the most favourable moment. 2.Method without solvent, convenient for unreactive alcohols, such as i-butanol: water is evaporated from glyoxal solution (1 mol); the residue, alcohol (10 mol) and catalyst are refluxed with water azeotropic extraction. 3.Method without solvent and without water azeotropic extraction: dehydrated glyoxal (1 mol) is refluxed with alcohol (10 mol) and catalyst.This method is the most convenient for methanol and ethanol.This sample and inexpensive preparation of 2,2-dialkoxy ethanals prompted us to perform syntheses of difunctional molecules otherwise only tediously accessible, since easily obtained functionalized acetals can be hydrolysed to functionalized aldehydes which constitute interesting synthons.Hydride or catalytic reduction as well as organometallic reactions lead to alcohols, further hydrolysed into 2-hydroxy aldehydes or oxidized to give way finally to α-ketoaldehydes for which this method provides a general synthetic pathway.From the oximes, prepared by classical methods, nitriles and amines can be obtained.Starting directly from the aldahydes, amines may be prepared by hydrogenation in the presence of ammonia or amines.The reaction of 2,2-dialkoxy ethanals with amides provides hydroxy and alkoxy acetal amides.The Cannizzaro reaction was also investigated; the same reactivity is displayed by formaldehyde and glyoxal monoacetals.Other reactions, among which Wittig and Wittig-Horner, are presently being studied in our laboratory.
A ONE POT PROCESS FOR THE OBTENTION AND REACTIONS OF GLYOXAL MONOACETAL
Bernard, Didier,Doutheau, Alain,Gore, Jacques
, p. 1807 - 1814 (2007/10/02)
A THF solution of glyoxal monoacetal 1 is obtained by SWERN oxidation of 2,2-diethoxy 1-ethanol and directly submitted to diverse nucleophilic species; The expected adducts of 1 are obtained with acceptable yields.
DISSYMETRATION DE LA MOLECULE DU GLYOXAL 1-SYNTHESE ET REACTIVITE DE L'ACETOXY-1 TRIETHOXY-1,2,2 ETHANE
Stambouli, A.,Chastrette, F.,Amouroux, R.,Chastrette, M.,Mattioda, G.,Blanc, A.
, p. 4149 - 4152 (2007/10/02)
Acetoxy-1 triethoxy-1,2,2 ethane, a dissymetric derivative of glyoxal, is prepared and reacted with various bases and nucleophiles, as amines, cyanotrimethylsilane, organometallic and WITTIG reagents.Various acetals are obtained, leading to α-fonctionalized aldehydes.
Reactions with Phosphine Alkylenes, 44. A Further Synthesis of (Z)-α,β-Unsaturated Aldehydes
Bestmann, Hans Juergen,Ermann, Peter
, p. 3264 - 3266 (2007/10/02)
Reaction of phosphorus ylides 4, especially such with electron donating groups R, with the glyoxal semiacetal 5 leads Z-stereospecifically to the formation of the acetals 3, which can be cleaved to the (Z)-α,β-unsaturated aldehydes 6.
