Synthesis and rearrangements of vinylcyclopropanes in a [2+3] cyclopentene and oxycyclopentene annulation methodology approach to (-)- specionin
dc.contributor.author | Fleming, Alison A. | en |
dc.contributor.committeechair | Hudlicky, Tomas | en |
dc.contributor.committeemember | Wolfe, James F. | en |
dc.contributor.committeemember | Mason, John G. | en |
dc.contributor.committeemember | Tanko, James M. | en |
dc.contributor.committeemember | White, Robert H. | en |
dc.contributor.department | Chemistry | en |
dc.date.accessioned | 2015-07-09T20:43:50Z | en |
dc.date.available | 2015-07-09T20:43:50Z | en |
dc.date.issued | 1989 | en |
dc.description.abstract | The addition of lithium dienolate 130, formed from ethyl 2-bromocrotonate, to enones and aldehydes yielding vinylcyclopropanes and vinyloxiranes was optimized. Various methods, pyrolytic and nonpyrolytic, were examined for the rearrangement of the resulting vinylcyclopropanes to cyclopentenes in an overall [2+3] annulation sequence. During the course of these studies, a new rearrangement pathway of these vinylcyclopropanes to bridged [3.2.n] bicyclic systems was discovered thus establishing a new [3+4] annulation technology. The extension of the [2+3] annulation technology to oxygenated cyclopentanoids was addressed. Several ethyl 2-bromo-4-oxycrotonates were synthesized, and the reaction of their lithium dienolates (217) with enones was investigated. The rearrangement of the resulting enol ether terminated vinylcyclopropanes to oxygenated cyclopentenes was also examined. [see document for diagram of chemical reaction] The application of this methodology was expressed in a synthetic approach to (-)-specionin (109). The key steps in this synthesis involved the cyclopropanation of optically pure enone 147 with Iithium dienolate 155 to give vinylcyclopropanes 169-exo/endo and the rearrangement of 169 to the oxygenated cyclopentanoid 187-exo which possesses the correct stereochemistry for further elaboration to epoxy acetate 216, an intermediate in a reported synthesis of specionin. [see document for diagrams of chemical reactions] | en |
dc.description.degree | Ph. D. | en |
dc.format.extent | vi, 171 leaves | en |
dc.format.mimetype | application/pdf | en |
dc.identifier.uri | http://hdl.handle.net/10919/54358 | en |
dc.language.iso | en_US | en |
dc.publisher | Virginia Polytechnic Institute and State University | en |
dc.relation.isformatof | OCLC# 21063568 | en |
dc.rights | In Copyright | en |
dc.rights.uri | http://rightsstatements.org/vocab/InC/1.0/ | en |
dc.subject.lcc | LD5655.V856 1989.F647 | en |
dc.subject.lcsh | Cyclopropane -- Research | en |
dc.subject.lcsh | Specionin -- Synthesis | en |
dc.title | Synthesis and rearrangements of vinylcyclopropanes in a [2+3] cyclopentene and oxycyclopentene annulation methodology approach to (-)- specionin | en |
dc.type | Dissertation | en |
dc.type.dcmitype | Text | en |
thesis.degree.discipline | Chemistry | en |
thesis.degree.grantor | Virginia Polytechnic Institute and State University | en |
thesis.degree.level | doctoral | en |
thesis.degree.name | Ph. D. | en |
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