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Item Description Banaag, April Rose en_US 2011-07-21T23:04:32Z 2011-07-21T23:04:32Z 2008 en_US
dc.identifier.isbn 9780549808329 en_US
dc.description Thesis (Ph.D.)--University of Hawaii at Manoa, 2008. en_US
dc.description Five-membered rings are common structural motifs in many important natural products. In general, the synthesis of highly functionalized five-membered rings, particularly with stereocontrol, is not as highly developed as that for six-membered rings. Thus, the pursuit of new methodologies towards this end is of great importance in synthetic chemistry. While there are several strategies for making five-membered rings, the Nazarov reaction is one that is particularly efficient in installing multiple stereogenic centers through a single operation. This thesis describes some recent progress for this reaction. en_US
dc.description In Chapter 1, the Nazarov reaction is introduced. A mechanism of the reaction is first described and a discussion of recent advances follows. The recent advances are discussed in the context of new variations of the reaction and the pioneering work towards asymmetric cyclopentannelation. en_US
dc.description In Chapter 2, we discuss how the synthesis and screening of a number of sugar-derived auxiliaries have paved the way to two superior chiral auxiliaries for the allene and the optimization of the reaction conditions for the Nazarov cyclization. The scope of each sugar-derived allene under the optimized conditions has been demonstrated through their reactions with a variety of morpholino enamides and in one case, an alpha,beta-unsaturated butyrolactone. Additionally, we report a more detailed, well-substantiated mechanistic hypothesis for the asymmetric allenyl ether Nazarov reaction that rationalizes the stereochemical outcome of our products. This model will aid in the design of simpler chiral allenyl ethers with non-sugar based scaffolds. en_US
dc.description In Chapter 3, we describe a triply-convergent cyclopentannelation reaction. This work is an extension of an existing methodology developed by our group that expands the scope and versatility of our allenyl ether Nazarov reaction. en_US
dc.description Lastly, in Chapter 4 we discuss ongoing work towards the development of a catalytic asymmetric Nazarov cyclization. Two approaches are described using alpha-alkoxy-substituted divinyl ketones. In the first approach, asymmetry is introduced through the use of chiral oxophilic Lewis acids. In the second approach, chiral ligands are employed as a means for transferring chiral information in our unique palladium(II)-catalyzed Nazarov reaction. en_US
dc.description Includes bibliographical references. en_US
dc.description Also available by subscription via World Wide Web en_US
dc.description 233 leaves, bound 29 cm en_US
dc.language.iso en-US en_US
dc.relation Theses for the degree of Doctor of Philosophy (University of Hawaii at Manoa). Chemistry; no. 5091 en_US
dc.rights All UHM dissertations and theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission from the copyright owner. en_US
dc.title Nazarov reaction : Development towards asymmetric cyclopentannelation using chiral auxiliaries and metal catalysis en_US
dc.type Thesis en_US
dc.type.dcmi Text en_US

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