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Showing 1 to 18 of 18 for “"allylic alcohol"”.
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A scalable protocol for the synthesis and use of neomenthyldiphenylphosphine.
… coupling of alkyne 3 and aldehyde 4 to afford allylic alcohol 5 in high yield and enantiomeric excess. Several important modifications were made to the initially communicated procedure in order to effectively translate this methodology from the millimole to decimole scale. Allylic alcohol 5 was …
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Nickel-catalyzed coupling reactions and synthetic studies toward ent-dioxepandehydrothyrsiferol via an epoxide-opening cascade
… coupling represent two methods of preparing allylic alcohols. Most asymmetric transition metal-catalyzed methods of preparing enantiomerically enriched allylic alcohols rely on chiral ligands. The nickel-catalyzed allene--aldehyde coupling exploits the axial chirality in 1,3-disubstituted …
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Studies directed towards the total synthesis of (+)-sieboldine A
… about the newly formed tertiary allylic alcohol ... The hydrindane product from this reductive cyclization can be transformed into the tetracyclic N,O-acetal which is two steps removed from the natural product 1. Efforts directed towards completion of the synthesis of 1 via a …
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Synthesis of nucleoside analogues.
… of furan C-nucleosides. The key carbocyclic allylic alcohol intermediate 5-methoxymethylcyclopent-2-enol was synthesized via a six step synthesis in racemic form from the ethylene-acetal of 2-methoxymethylcyclopentanone but attempts at deprotection of the methyl ether proved unsuccessful. …
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The Synthetic Utility of Enol Derivatives and the Directed Aryltitanation of Homoallylic and Allylic Alcohols
… is less developed. Directing groups, such as homoallylic and allylic alcohols, may help overcome the poor reactivity of alkenes towards carbometalation. Herein the alcohols direct a highly diastereoselective aryltitanation to the proximal carbon–carbon double bond. Reactions with homoallylic …
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Strategies towards the synthesis of prostaglandin analogues
… to be low yielding, the reaction between the allylic alcohol and butadiene sulfone proceeded readily and in high yield. The derived cycloadduct represents a late-stage intermediate for the synthesis of isoprostanes. Methodologies to perform cis-hydroxylation followed by oxidative cleavage of …
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Enantioselective nickel-catalyzed reductive coupling reactions of alkynes and aldehydes. Synthesis of amphidinolides T1 and T4 via catalytic, stereoselective macrocyclizations
… Reductive Couplings of Alkynes and Aldehydes Allylic alcohol synthesis via a nickel-catalyzed reductive coupling reaction of alkylsubstituted alkynes and aldehydes was studied for ligand effects with respect to the regioselectivity and enantioselectivity of the coupling process. A class of …
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Generating structural diversity in \(\alpha\)[alpha],\(\alpha\)[alpha]-difluoromethyl ketones
… of a special protecting group for the allylic alcohol was essential, as was control of the pH of the reaction medium.
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Studies towards the total synthesis of Antascomicin A.
… with the C1rC24 vinyl iodide to form the C10-C24 allylic alcohol are detailed, and the subsequent synthesis of the protected C10-C24 fragment is described. Investigations into the synthesis of the C25-C34 fragment are also presented. The coupling of a model stannane with the novel C30-C33 tartrate …
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The Total Synthesis of Pseudonocardia sp. Quinolone Natural Products and Studies Towards the Total Synthesis of 1β-Hydroxyalantolactone
… and acid catalysed 1,3-transposition of an allylic alcohol. In the second section, attention turns towards the total synthesis of the complex sesquiterpene lactone 1β-Hydroxyalantolactone. The compound possesses five stereogenic centres, one of which is quaternary, alongside a challenging …
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Exploration of Carbon-oxygen and Carbon-nitrogen Bond Formation Utilizing Trichloroacetimidates and Investigations of New Reactions Mediated By Oxoammonium Salts
… of these alkylations with tertiary halides or alcohols are very low. A new protocol was developed utilizing trichloroacetamide electrophiles to install bulky groups onto one of the phenolic oxygens. Trichloroacetimidates are also shown to be useful reactions for the synthesis of esters. These …
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Total syntheses of (+̲)-Methyl cantabrenonate, (+̲)-Methyl epoxycantabronate, and (+̲)-Crinipellin B
… by treatment with n-BuLi in THF. The resultant allylic alcohol 249 underwent oxidative rearrangement to furnish the enedione 267. Two synthetic steps provided the enedione epoxide 188, which was converted into (±)-crinipellin B (15).
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Anion Relay Cyclopropanation and Aryl Vinyl Cyclopropane Cope Rearrangements
… with an overview of retro-Claisen activation of allylic alcohols and its application to decarboxylative and deacylative allylation reactions (DcA and DaA). This synopsis is followed by an overview of a novel anion relay cyclopropanation accomplished through a retro-Claisen activation of a nascent …
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Studies in Synthesis and Organocatalysis: (i) The Design and Synthesis of Novel Electron Deficient Dienes and their Application in the First Enamine Activated Organocatalytic 1,6-Conjugate Addition. (ii) The Development of a New Organocatalytic Methodology through the Combination of DNA-Based Catalysis and Organocatalysis
… The step involving the oxidation of a homo-allylic alcohol remains to be solved. Interestingly a DMSO-based oxidation generated a sulfur ylide in high yield (90%), a possible explanation is provided. A second class of butadienes, bis-cyano butadienes, that are suitable substrates for …
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DESIGN, SYNTHESIS, AND OPTIMIZATION OF SMALL-MOLECULE CD4 MIMETICS AS HIV-1 ENTRY INHIBITORS AND SYNTHETIC EFFORTS TOWARD THE TOTAL SYNTHESIS OF NAHUOIC ACID Cii
… united by a Micalizio alkoxide-directed alkyne–allylic alcohol coupling, forging the critical C–C bond with high stereoselectivity. Olefin metathesis using an alternative substrate envisioned to overcome the challenges previously encountered in ester installation and thereby complete the total …
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Synthesis and reactivities of titanocene-oxo complexes and rhodium-catalyzed oxidative amidation
… metal-catalyzed amidation of aldehydes and alcohols is a promising method for greener, more atom-economical amide synthesis and thus is of great interest to our group. The objective here is to address the current drawbacks in this research area, including: (i) low reactivity of sterically …
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Asymmetric Transfer Hydrogenation of Secondary Allylic Alcohols
… method that transforms racemic secondary allylic alcohols into optically active secondary alcohols. The key step in this methodology occurs through a ruthenium catalyzed tandem isomerization and asymmetric transfer hydrogenation reaction. This reaction is a one pot, two-step process, which …
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Applications of Green Chemistry in Asymmetric Transfer Hydrogenation and Chiral Separations
… and analytical chemistry. More specifically, allylic and chiral alcohols are abundant in natural sources such as in essential oils, and widely utilized as starting materials. They are also major components in food, fragrance, biocides and the pharmaceutical compounds. In this thesis, I report …