75233-61-3Relevant academic research and scientific papers
Catalytic Asymmetric Synthesis of Isoxazolines from Silyl Nitronates
Han, Xiaoyu,Dong, Li,Geng, Caiwei,Jiao, Peng
supporting information, p. 3194 - 3197 (2015/07/15)
1,3-Dipolar cycloadditions of triisopropylsilyl nitronates and 2-alkylacroleins produced isoxazolines bearing a chiral quaternary center in high yields and enantioselectivities with the aid of a chiral oxazaborolidine catalyst. One chiral isoxazoline product was converted to (R)-(+)-Tanikolide in 9 steps in a total yield of 43%. (Chemical Equation Presented).
Chemoselective tetrahydropyranylation of primary alcohols under freezing water pressure
Boruwa, Joshodeep,Bhuyan, Ranjana,Gogoi, Naminita,Barua, Nabin C.
, p. 331 - 334 (2007/10/03)
A highly efficient environmentally friendly method for selective tetrahydropyranylation of primary alcoholic groups under pressure exerted by freezing water has been described.
A novel approach to bis-isoxazolines using a latent form of cyclopentadienone
Basra, Sanjivanjit K.,Drew, Michael G.B.,Mann, John,Kane, Peter D.
, p. 3592 - 3598 (2007/10/03)
The synthesis of a range of both racemic and homochiral 4-alkyl- and 4-aryl-8-hydroxy-2-oxa-3-azabicyclo[3.3.0]oct-3-en-6-ones (isoxazolines) from the 1,3-dipolar cycloaddition reactions between alky- and aryl-nitrile oxides and 4-alkoxycyclopent-2-enomes was described. Elimination of the 8-hydroxy group and subsequent additional cycloaddition reactions provided 5,9-disubstituted-3,11-dioxa-4,10-diazatricyclo[6.3.01,8.02 ,6]undeca-4,9-dien-7-ones formally derived fromcyclopentadienone. The results showed that in the structures studied the nonhydrogen atoms were included in geometric positions and given thermal parameters equivalent to 1.2 times those of the atoms to which they were attached.
Solvent free tetrahydropyranylation of phenols and alcohols over zeolites HSZ as reusable catalysts
Ballini, Roberto,Bigi, Franca,Carloni, Silvia,Maggi, Raimondo,Sartori, Giovanni
, p. 4169 - 4172 (2007/10/03)
Phenols and alcohols are tetrahydropyranylated in the presence of zeolites HSZ in good to excellent yields and selectivities. Addition of methanol performs the complete deprotection.
An alternative isoxazole route to α-alkoxycarbonyl-β-diketones
Jones, Raymond C. F.,Dunn, Stephen H.,Duller, Kathryn A. M.
, p. 1319 - 1321 (2007/10/03)
Cycloaddition of oxygen-functionalized nitrite oxides to the enamine from ethyl acetoacetate produces 4-ethoxycarbonyl-5-methylisoxazoles carrying a 3-tetrahydropyranyloxymethyl, 3-diethoxymethyl or 3-ethoxycarbonyl substituent; the 3-formylisoxazole is prepared from the former two and condensed in situ with phosphoranes to give 3-alkenylisoxazoles that are cleaved by hexacarbonylmolybdenum or hydrogenolysis to afford α-alkoxycarbonyl-β-diketones.
Methods for the Stereoselective Cis Cyanohydroxylation and Carboxyhydroxylation of Olefins
Kozikowski, Alan P.,Adamczyk, Maciej
, p. 366 - 372 (2007/10/02)
Two valuable reagents for the cis-specific vicinal cyanohydroxylation and carboxyhydroxylation of olefins are described.The cyanohydroxylation process is based on the decarboxylative ring opening of 3-carboxyisoxazolines prepared by the cycloaddition reaction of carbethoxyformonitrile oxide with various alkenes.Fragmentation of the isoxazolines prepared from cis- and trans-2-butene has been found to occur without any crossover in stereochemistry.The carboxyhydroxylation process begins with the dipolar cycloaddition reaction of the nitrile oxide derived from thetetrahydropyranyl ether derivative of 2-nitroethanol.Deprotection, hydrogenation, and oxitative cleavage of the derived dihydroxy ketone yield the stereochemcally pure β-hydroxy carboxylic acid.
Synthetic Studies toward Verrucarol. 1. Synthesis of the AB Ring System
Kraus, George A.,Frazier, Kevin
, p. 4820 - 4825 (2007/10/02)
A synthetic route to the AB ring system of verrucarol is described.After two routes employing intramolecular cyclization failed, the Diels-Alder reaction of methyl coumalate and isoprene afforded bicyclic lactone 13.Transformation of 13 into hydroxy lacto
