Iterative strategies toward the synthesis of fused ether ring systems and the synthesis of fused ether containing natural products

Persistent Link:
http://hdl.handle.net/10150/280230
Title:
Iterative strategies toward the synthesis of fused ether ring systems and the synthesis of fused ether containing natural products
Author:
Allwein, Shawn Paul
Issue Date:
2001
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
A highly efficient and general approach to fused ether ring systems has been presented. The approach couples stereoselective C-glycoside forming reactions with subsequent annulations. C-glycosides were formed from glycals through an oxidation and carbon-carbon bond forming sequence. Annulations involving a two step methylenation/enol ether-olefin ring closing metathesis or a single flask, acid mediated cyclization/elimination proved to be efficient tribenzyl- D-glucal (95), [4.4.0] and [4.5.0] bicyclic enol ethers (194, 200, 204) were stereoselectively generated in 2-4 steps in good overall yields (53%, 57%, and 39% respectively). Iteration resulted in the stereoselective formation of tricylic enol ethers (240, 241). In addition, our C-glycoside approach was applied to the synthesis of fused ether containing natural products. A formal synthesis of (±)-hemibrevetoxin B (2) was achieved by intercepting Mori's intermediate ( 278) in 21 steps and 3.8% overall yield. The C-glycoside approach to fused ethers was also demonstrated in the synthesis of halichondrin B's model compounds, bicycle 374 and tricycle 383. Subsequent fragmentation of 383 resulted in bicyclic alcohol 384 which correlates to the C,23-C,38 subunit of halichondrin B (8).
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Chemistry, Organic.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Chemistry
Degree Grantor:
University of Arizona
Advisor:
Rainier, Jon D.

Full metadata record

DC FieldValue Language
dc.language.isoen_USen_US
dc.titleIterative strategies toward the synthesis of fused ether ring systems and the synthesis of fused ether containing natural productsen_US
dc.creatorAllwein, Shawn Paulen_US
dc.contributor.authorAllwein, Shawn Paulen_US
dc.date.issued2001en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractA highly efficient and general approach to fused ether ring systems has been presented. The approach couples stereoselective C-glycoside forming reactions with subsequent annulations. C-glycosides were formed from glycals through an oxidation and carbon-carbon bond forming sequence. Annulations involving a two step methylenation/enol ether-olefin ring closing metathesis or a single flask, acid mediated cyclization/elimination proved to be efficient tribenzyl- D-glucal (95), [4.4.0] and [4.5.0] bicyclic enol ethers (194, 200, 204) were stereoselectively generated in 2-4 steps in good overall yields (53%, 57%, and 39% respectively). Iteration resulted in the stereoselective formation of tricylic enol ethers (240, 241). In addition, our C-glycoside approach was applied to the synthesis of fused ether containing natural products. A formal synthesis of (±)-hemibrevetoxin B (2) was achieved by intercepting Mori's intermediate ( 278) in 21 steps and 3.8% overall yield. The C-glycoside approach to fused ethers was also demonstrated in the synthesis of halichondrin B's model compounds, bicycle 374 and tricycle 383. Subsequent fragmentation of 383 resulted in bicyclic alcohol 384 which correlates to the C,23-C,38 subunit of halichondrin B (8).en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectChemistry, Organic.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineChemistryen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorRainier, Jon D.en_US
dc.identifier.proquest3010215en_US
dc.identifier.bibrecord.b4161172xen_US
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