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Mohammad Movassaghi. Han, Sunkyu, 1982- Massachusetts Institute of Technology. Dept. of Chemistry. Massachusetts Institute of Technology. Department of Chemistry 2012-09-27T15:24:41Z 2012-09-27T15:24:41Z 2012 2012 http://hdl.handle.net/1721.1/73356 809537907 Thesis (Ph. D. in Organic Chemistry)--Massachusetts Institute of Technology, Dept. of Chemistry, 2012. Vita. Cataloged from PDF version of thesis. Includes bibliographical references. I. Total Synthesis of the (-)-Agelastatin Alkaloids The pyrrole-imidazole family of marine alkaloids, derived from linear clathrodin-like precursors, constitutes a diverse array of structurally complex natural products. The bioactive agelastatins are members of this family that possess a tetracyclic molecular framework incorporating C4-C8 and C7-N12 bond connectivities. We provide a hypothesis for the formation of the unique agelastatin architecture that maximally exploits the intrinsic chemistry of plausible biosynthetic precursors. We report the concise enantioselective total syntheses of all known agelastatin alkaloids including the first total syntheses of agelastatins C, D, E, and F. Our gram-scale chemical synthesis of agelastatin A was inspired by our hypothesis for the biogenesis of the cyclopentane C-ring and required the development of new transformations including an imidazolone-forming annulation reaction and a carbohydroxylative trapping of imidazolones. II. Total Synthesis of the (-)-Trigonoliimine Alkaloids The concise and enantioselective total syntheses of (-)-trigonoliimines A, B, and C are described. Our unified strategy to all three natural products is based on asymmetric oxidation and reorganization of a single bistryptamine, a sequence of transformations with possible biogenetic relevance. We revise the absolute stereochemistry of (-)-trigonoliimines A, B, and C. by Sunkyu Han. Ph.D. in Organic Chemistry p. eng Massachusetts Institute of Technology M.I.T. 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. See provided URL for inquiries about permission. http://dspace.mit.edu/handle/1721.1/7582 Chemistry. Enantioselective total Synthesis of the agelastatin and trigonoliimine alkaloids Thesis application/pdf false Publication unknown unknown <Publication xmlns="https://www.openaire.eu/cerif-profile/1.1/" id="fbf72643-2b6d-4af7-9567-e8281000956e"> <Type xmlns="https://www.openaire.eu/cerif-profile/vocab/COAR_Publication_Types">http://purl.org/coar/resource_type/c_1843</Type> <Language>eng</Language> <Title>Enantioselective total Synthesis of the agelastatin and trigonoliimine alkaloids</Title> <PublishedIn> <Publication> </Publication> </PublishedIn> <PublicationDate>2012</PublicationDate> <Authors> <Author> <DisplayName>Han, Sunkyu, 1982-</DisplayName> <Affiliation> <OrgUnit> </OrgUnit> </Affiliation> </Author> </Authors> <Editors> </Editors> <Publishers> <Publisher> <DisplayName>Massachusetts Institute of Technology</DisplayName> <OrgUnit /> </Publisher> </Publishers> <License>http://dspace.mit.edu/handle/1721.1/7582</License> <Keyword>Chemistry.</Keyword> <Abstract>I. Total Synthesis of the (-)-Agelastatin Alkaloids The pyrrole-imidazole family of marine alkaloids, derived from linear clathrodin-like precursors, constitutes a diverse array of structurally complex natural products. The bioactive agelastatins are members of this family that possess a tetracyclic molecular framework incorporating C4-C8 and C7-N12 bond connectivities. We provide a hypothesis for the formation of the unique agelastatin architecture that maximally exploits the intrinsic chemistry of plausible biosynthetic precursors. We report the concise enantioselective total syntheses of all known agelastatin alkaloids including the first total syntheses of agelastatins C, D, E, and F. Our gram-scale chemical synthesis of agelastatin A was inspired by our hypothesis for the biogenesis of the cyclopentane C-ring and required the development of new transformations including an imidazolone-forming annulation reaction and a carbohydroxylative trapping of imidazolones. II. Total Synthesis of the (-)-Trigonoliimine Alkaloids The concise and enantioselective total syntheses of (-)-trigonoliimines A, B, and C are described. Our unified strategy to all three natural products is based on asymmetric oxidation and reorganization of a single bistryptamine, a sequence of transformations with possible biogenetic relevance. We revise the absolute stereochemistry of (-)-trigonoliimines A, B, and C.</Abstract> <Access xmlns="http://purl.org/coar/access_right" > </Access> </Publication>