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dc.identifier.urihttp://hdl.handle.net/1951/59726
dc.identifier.urihttp://hdl.handle.net/11401/71266
dc.description.sponsorshipThis work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree.en_US
dc.formatMonograph
dc.format.mediumElectronic Resourceen_US
dc.language.isoen_US
dc.publisherThe Graduate School, Stony Brook University: Stony Brook, NY.
dc.typeDissertation
dcterms.abstractDespite a growing interest in biological activities of natural products that contain the bicyclo[4.2.0]octadiene ring system such as SNF 4435 C and SNF 4435 D, an asymmetric version of 8??, 6?? electrocyclization has remained unattained. While investigating (2E,4Z,6Z,8E)-tetraene substrates bearing amide- or oxazoline-based chiral auxiliaries, a rationally designed chiral 4,5-trans-diphenyl oxazoline auxiliary provided an impressive stereoselectivity (70 de%) in the 8?? ring closure. Confirmation of the major isomer from the diastereomeric bicyclooctadienes was determined based on X-ray structure analysis of a SNF analog bearing (S)-phenylglycinol moiety. This first example of chiral induction generated by the trans-4,5-diphenyl oxazoline auxiliary in 8?? electrocyclization directly affords enantiomeric carboxylic acids (R = CO2H) which are key intermediates for elaboration to stereochemically homogeneous analogs of the SNF multidrug-resistance reversal agents. On the other hand, asymmetric Shi epoxidation and aspartate-catalyzed asymmetric epoxidation were adopted to convert racemic SNF analogs to their enantiomerically pure forms. While synthesizing the highly substituted cyclobutane core of bielschowskysin, tetraene substrates with 1,2-fused ring were cyclized to leading exclusively to endo products in the 8??, 6?? electrocyclization. In addition, the double ring closure was critically influenced by the methyl group adjacent to the aryl group. Progress toward the total synthesis of (+/-)-kingianin A, which is interested in its unique pentacyclic framework and potential biological activity, has been focused on model-based testing for 8??, 6?? electrocyclization and cation radical catalyzed Diels-Alder reaction. This issue is currently under active investigation in our laboratory.
dcterms.available2013-05-22T17:34:55Z
dcterms.available2015-04-24T14:46:46Z
dcterms.contributorParker, Kathlyn Aen_US
dcterms.contributorGoroff, Nancy Sen_US
dcterms.contributorDrueckhammer, Dale Gen_US
dcterms.contributorCarpino, Nicholas.en_US
dcterms.creatorKim, Keunsoo
dcterms.dateAccepted2013-05-22T17:34:55Z
dcterms.dateAccepted2015-04-24T14:46:46Z
dcterms.dateSubmitted2013-05-22T17:34:55Z
dcterms.dateSubmitted2015-04-24T14:46:46Z
dcterms.descriptionDepartment of Chemistryen_US
dcterms.extent278 pg.en_US
dcterms.formatMonograph
dcterms.formatApplication/PDFen_US
dcterms.identifierhttp://hdl.handle.net/1951/59726
dcterms.identifierKim_grad.sunysb_0771E_11135en_US
dcterms.identifierhttp://hdl.handle.net/11401/71266
dcterms.issued2012-12-01
dcterms.languageen_US
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dcterms.publisherThe Graduate School, Stony Brook University: Stony Brook, NY.
dcterms.subjectaymmetric synthesis
dcterms.subjectOrganic chemistry
dcterms.titleStereocontrolled Synthesis of Bicyclo[4.2.0]octadienes for SNF 4435 C and D Analogs, Bielschowskysin, and (+/-)-Kingianin A
dcterms.typeDissertation


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