38461-13-1Relevant academic research and scientific papers
Morpholinosulfur trifluoride (morph-DAST)-mediated rearrangement in the fluorination of cyclic α,α-dialkoxy ketones toward 1,2-dialkoxy-1,2-difluorinated compounds
Surmont, Riccardo,Verniest, Guido,De Groot, Alex,Thuring, Jan Willem,De Kimpe, Norbert
scheme or table, p. 2751 - 2756 (2010/12/25)
The deoxofluorination of cyclic α,α-dialkoxy ketones with morpholinosulfur trifluoride (Morph-DAST) resulted in 1,2-dialkoxy-1,2- difluorinated carbo- and heterocyclic compounds. The reaction proceeds via a 1,2-alkoxy migration leading to mixtures of cis-
MACROCYCLIC PYRIMIDINE DERIVATIVES
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Page/Page column 87, (2009/10/17)
Macrocyclic pyrimidine compounds, compositions comprising such compounds, methods for making the compounds, and methods of treating and preventing the progression of diseases, conditions, and disorders using such compounds and compositions are described h
High-pressure-promoted uncatalyzed ketalization of ketones and oxy-Michael/ketalization of conjugated enones
Kumamoto, Koji,Ichikawa, Yoshiyasu,Kotsuki, Hiyoshizo
, p. 2254 - 2256 (2007/10/03)
A new practical method for ketalization or oxy-Michael/ketalization was developed using the high-pressure-promoted condensation of ketones or α,β-unsaturated ketones with alcohols in the presence of trialkyl orthoformates as water scavengers. Georg Thieme Verlag Stuttgart.
Intramolecular 4+3 cycloadditions. A cyclohexenyl cation, its halogenated congener and a quasi-Favorskii rearrangement
Harmata, Michael,Bohnert, Gary,Kürti, Laszlo,Barnes, Charles L.
, p. 2347 - 2349 (2007/10/03)
Treatment of alkoxycyclohexenols bearing a tethered diene substituent with a Lewis acid results in intramolecular 4+3 cycloaddition with complete endo selectivity. A cycloadduct bearing a bromo substituent at a bridgehead position undergoes a quasi-Favorskii rearrangement in near quantitative yield upon reaction with lithium aluminum hydride.
Process for the preparation of α-diketones from ketols or ketals from ketols
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, (2008/06/13)
The process for the preparation of carbonyl compounds of the formula I where R1and R2are a hydrocarbon radical, or R1and R2together are an unsubstituted or substituted alkylene group, and X is=O or two alkoxy groups, comprises oxidizing alcohols of the formula II where R1to R2and X are as defined above, with oxygen in the gaseous phase a) at temperatures of from 270 to 600° C. on silver coated catalysts which comprise an abrasion-resistant coating of metallic silver on a core of inert support material, or b) at temperatures of from 450 to 750° C. on silver crystals and/or copper crystals having a particle size of from 0.1 to 2.5 mm for a residence time of at most 0.1 second. Also claimed is an advantageous overall process for the preparation of α-diketones, preferably diacetal, from the corresponding ketone, in particular methyl ethyl ketone, via the carbonyl compounds of the formula I where X is two alkoxy groups.
Reaction of dimethoxycarbene with strained cyclic carbonyl compounds
Venneri,Warkentin
, p. 1194 - 1203 (2007/10/03)
A cyclopropanone, a cyclopropenone, cyclobutanones, a cyclobutane-1,3-dione, and a cyclobutene-1,2-dione reacted with dimethoxycarbene to afford acetals of the next larger ring by formal insertion of the carbene into a C-C bond α to the carbonyl group. When either of two saturated α-ring carbons could be involved in the process, the ring expansion was selective, affording primarily the product of apparent insertion into the more substituted ring bond. With 2,3-dimethoxycyclobutene-1,2-dione, insertion occurred between the carbonyl groups and with β-propiolactone it occurred at the lactone bond. β-Propiolactam, however, reacted by insertion of the carbene into the N-H bond.
The reaction of enaminones with grignard reagents: Synthesis of α,β- unsaturated ketones
Fontenas,Ait-Haddou,Bejan,Balavoine
, p. 1743 - 1753 (2007/10/03)
Enaminones in toluene react with Grignard reagents in tetrahydrofuran at 0-25 °C, to give selectively and with high yields the corresponding α,β- unsaturated ketones.
An efficient synthesis of 2-(methylaminomethyl)-4,5-dialkyl-1H-imidazoles
Reader, Valérie A.
, p. 1077 - 1078 (2007/10/03)
A mild and convenient synthesis of 2-(methylaminomethyl)-4,5-dialkyl-1H-imidazoles is described. The procedure was used in the preparation of 2-(methylaminomethyl)-4,5,6,7-tetrahydro-1H-benzimidazole 1 and 2-(methylaminomethyl)-4,5-dimethyl-1H-imidazole 2
Biotransformation of αβ-unsaturated carbonyl compounds: sulfides, sulfoxides, sulfones, nitriles and esters by yeast species: carbonyl group and carbon-carbon double bond reduction
Koul, Surinder,Crout, David H. G.,Errington, William,Tax, Jiri
, p. 2969 - 2988 (2007/10/03)
The reduction of αβ-unsaturated ketones with γ-sulfide, sulfoxide, sulfone, nitrile and ester functions has been investigated.Both C=O and C=C reduction was observed.In the sulfur series, C=O bond reduction was always observed, but significant C=C bond reduction was observed only with the sulfide.The unsaturated nitriles gave the corresponding alcohols as the major bioreduction product, with smaller but significant amounts of fully reduced product.A similar result was obtained with the ester substrate.Relative and absolute configurations of bioreduction products were determined.A comparison was made between reductions catalysed by bakers' yeast (Saccharomyces cerevisiae) and by other yeasts (Zygosaccharomyces rouxii, Pichia capsulata, P. farinosa, Candida chalmersi and C. diddensiae).The tendency of Z. rouxii to give products enantiomeric with thouse obtained using S. cerevisiae was noted.The relationship between substrate structure and the stereochemistry of C=C double bond reduction is discussed.
Ring-Chain Tautomerism Provides a Route to 7a-Hydroxy-3a-methyl-2,7-dioxoperhydrobenzofuran. Synthesis of the Hydroxy γ-Lactone Substructure of Myrocin and Other Bioactive Natural Products
Langschwager, Wolf,Hoffmann, H. Martin R.
, p. 797 - 802 (2007/10/02)
(2-Oxocyclohexyl)acetic acid 10 was converted into bicyclic alkoxy γ-lactones 12a-d via intermediate chloro lactone 11 and alkanolysis.Similarly, lactones 15a,b and 18 were prepared.In contrast, simple ring-chain tautomerism directly afforded the title heterocycle 28, a crystalline, stable and welldefined compound.The angular methyl group seems essential for the spontaneous lactonization. 5,5-Dialkoxy-4-oxocarboxylic acids 26a, b without an angular methyl group did not cyclize to bicyclic hydroxy γ-lactones. - Key Words: Hydroxy lactone, 5-membered, (lactol) tautomer / 4-Oxocarboxylic acids / Keto-cyclol tautomerism.
