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Showing 1 to 10 of 10 for “"Horner–Wadsworth–Emmons reaction"”.
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Synthetic Studies Towards the Gombaspiroketals and a Cobalt-Catalysed Epoxide Olefination
… elaboration to allylsilane 45 via intramolecular Horner-Wadsworth-Emmons reaction of 58 proceeded smoothly. Synthesis of aldehyde 303 en route to acetal 172 was investigated. The literature sequence reported from 2-methylcyclohexanone (299) was ineffective, due to presence of inseparable …
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Asymmetrische Synthese von 3-Oxa-15-Deoxy-16-(m-tolyl)-Tetranorisocarbacyclin und 15-Deoxy-16-(m-tolyl)-Tetranorisocarbacyclin
… copperorganyl to an azoalkene and an asymmetric Horner-Wadsworth-Emmons reaction using a chiral phosphonate.
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Multidentate phosphino-alkene ligands and their late transition metal complexes
… to be an impurity in the microwave-assisted Horner-Wadsworth-Emmons reaction of 2-(diphenylthiophosphine)benzaldehyde (136) with 1,3-bis-(ethoxyphosphonato)-acetone (130) to give of dbaTHIOPHOS (137) and an unexpected THF insertion product, 138. The latter is explained by a side reaction …
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Asymmetric synthesis of trisubstituted isoindolines and tetrahydropalmatine via tandem 1,2-addition-cyclisation
… was transformed into different alkenes by Horner-Wadsworth-Emmons reaction. Addition of a organolithium reagent/cerium chloride combination to a solution of the phenylsulfonyl vinyl SAMP-hydrazone yielded 32% of the methyl substituted and 47% of the n-butyl substituted …
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Studies Towards a Second-Generation Synthesis of the Aplyronines
… 159 with fewer manipulation steps. A refined reaction sequence featuring titanium aldol methodology and an enzymatic desymmetrisation process delivered multigram stocks of the C15-C27 aldehyde 161 upon scale- up, testifying to the robustness of the devised route. Synthesis of the C1-C14 …
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Radical Approaches to Alangium and Mitragyna Alkaloids
… of radical intermolecular and intramolecular reactions in synthesis. Consideration is given to the mediator of radical reactions from the classic organotin reagents, to more recently developed alternative hydrides. An overview of previous synthetic approaches to a range of Alangium and …
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Synthetic efforts toward the eastern hemisphere of theonellamide C
… utilizing a key Sharpless aminohydroxylation reaction. The eHyAsn building block, Boc-eHyAsn(OTBS)-OH, was coupled with HCl.Phe.OMe using EDC/HOBt/NEt3/THF to afford Boc-eHyAsn(OTBS)-Phe-OMe in 68% yield. Our two early approaches toward the …
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Organokatalytische Synthesen biologisch aktiver Naturstoffe : Totalsynthesen von Amaminol A und B und (+)-Mitsugashiwalacton sowie Synthesen 2,6-disubstituierter Tetrahydropyranen
… step by an intramolecular Diels-Alder reaction of a synthesised tetraenal with an imidazolidinone-derivative as effective organocatalyst and TFA as co-catalyst. This reaction yielded the desired indane core with high selectivity, high endo/exo-selectivity and a surplus of enantiomers of …
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Isomerization-Locked Alkene Analogues of Xaa–Pro Dipeptides in the Proteins Collagen and Bora
… aldol addition to cyclohexanone. A Mg2+-promoted Horner-Wadsworth-Emmons reaction afforded the (Z)-fluoro-alkene over the (E)-fluoro-alkene in about a 2:1 ratio. The two diastereomers, Fmoc–Gly–Ψ[(Z)CF=C]-L-Pro–Hyp(tBu)–OH and Fmoc–Gly–Ψ[(Z)CF=C]-D-Pro–Hyp(tBu)–OH were separated by supercritical …