{"id":{"repo_id":"alabama","oai_identifier":"oai:ir.ua.edu:123456789/1063"},"canonical_url":"https://search.dev.ndltd.org/etd/alabama/oai:ir.ua.edu:123456789/1063","repository":{"repo_id":"alabama","name":"University of Alabama","base_url":"https://ir-api.ua.edu/oai/request"},"display":{"title":"Syntheses of C-glycoside natural products via oxocarbenium cationic intermediates","abstract":"This dissertation highlights studies into the total synthesis of C-glycoside natural products via oxocarbenium cationic intermediates with a brief introduction given in the first chapter. The second chapter examines our approach to the first total synthesis and absolute configuration of the antibiotic (+)-bruguierol C. The key step is the diastereoselective capture of an in situ generated oxocarbenium cation via an intramolecular Marson-type Friedel-Crafts cyclization, which concomitantly generates the chiral quaternary center. The third chapter illustrates the formal syntheses of (+)-brussonol and (+)-abrotanone, attained in a convergent and concise manner, making these syntheses the shortest to date. The key step, as with (+)-bruguierol C, involves the diastereoselective capture of an in situ generated oxocarbenium cation via an intramolecular Marson-type Friedel-Crafts cyclization. A novel methodology that employs catalytic quantities of pyridinium tribromide (Py*Br3) in methanol to chemoselectively deprotect primary TBS ethers in the presence of a variety of other protecting groups and common functional groups is the subject of the fourth chapter. The formal synthesis of the unnatural (-)-neopeltolide core, whose natural antipode has been found to be extremely cytotoxic and has emerged as a promising anticancer lead is discussed in the fifth chapter. Efficient application of the Evans' protocol for the synthesis of 1,3-syn diols via an intramolecular hetero-Michael addition followed by reductive deprotection of the resulting benzylidene acetal allowed for swift access to the ä-lactone. Central to the synthetic approach is a tandem nucleophilic addition-diastereoselective axial reduction of an in situ generated oxocarbenium cation to construct the â-C-glycoside moiety of the neopeltolide core. The final chapter of this dissertation describes the total synthesis of the proposed structure of pochonin J, whose reported structure features a rare á-C-glycoside moiety embedded within a 14-membered macrolactone. Key steps of this convergent synthesis include a chemoselective Wacker oxidation, a stereoselective allylation of an oxocarbenium cation intermediate to assemble the á-C-glycoside fragment, and a ring-closing metathesis (RCM) reaction to forge the 14-membered macrolactone. During our studies directed towards its laboratory synthesis, it was found that the spectroscopic data of the synthesized compound does not correlate to the initially described natural product.","abstract_html":"This dissertation highlights studies into the total synthesis of C-glycoside natural products via oxocarbenium cationic intermediates with a brief introduction given in the first chapter. The second chapter examines our approach to the first total synthesis and absolute configuration of the antibiotic (+)-bruguierol C. The key step is the diastereoselective capture of an in situ generated oxocarbenium cation via an intramolecular Marson-type Friedel-Crafts cyclization, which concomitantly generates the chiral quaternary center. The third chapter illustrates the formal syntheses of (+)-brussonol and (+)-abrotanone, attained in a convergent and concise manner, making these syntheses the shortest to date. The key step, as with (+)-bruguierol C, involves the diastereoselective capture of an in situ generated oxocarbenium cation via an intramolecular Marson-type Friedel-Crafts cyclization. A novel methodology that employs catalytic quantities of pyridinium tribromide (Py*Br3) in methanol to chemoselectively deprotect primary TBS ethers in the presence of a variety of other protecting groups and common functional groups is the subject of the fourth chapter. The formal synthesis of the unnatural (-)-neopeltolide core, whose natural antipode has been found to be extremely cytotoxic and has emerged as a promising anticancer lead is discussed in the fifth chapter. Efficient application of the Evans' protocol for the synthesis of 1,3-syn diols via an intramolecular hetero-Michael addition followed by reductive deprotection of the resulting benzylidene acetal allowed for swift access to the ä-lactone. Central to the synthetic approach is a tandem nucleophilic addition-diastereoselective axial reduction of an in situ generated oxocarbenium cation to construct the â-C-glycoside moiety of the neopeltolide core. The final chapter of this dissertation describes the total synthesis of the proposed structure of pochonin J, whose reported structure features a rare á-C-glycoside moiety embedded within a 14-membered macrolactone. Key steps of this convergent synthesis include a chemoselective Wacker oxidation, a stereoselective allylation of an oxocarbenium cation intermediate to assemble the á-C-glycoside fragment, and a ring-closing metathesis (RCM) reaction to forge the 14-membered macrolactone. During our studies directed towards its laboratory synthesis, it was found that the spectroscopic data of the synthesized compound does not correlate to the initially described natural product.","abstract_has_math":false,"creators":["Martinez, Dionicio Solorio"],"institution":"University of Alabama Libraries","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":["Paley, Mark S.","Shaughnessy, Kevin H.","Snowden, Timothy S.","Thrasher, Joseph S."],"advisors":["Jennings, Michael P."],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011","date_published":"2011","updated_at":"2026-07-27T18:44:23Z","subjects":["Organic chemistry","Chemistry"],"languages":["en_US","English"],"rights":["All rights reserved by the author unless otherwise indicated."],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["u0015_0000001_0000558","Martinez_alatus_0004D_10710"],"render_values":[{"text":"u0015_0000001_0000558","href":null,"code":true},{"text":"Martinez_alatus_0004D_10710","href":null,"code":true}]}]},"links":{"outbound_url":"https://ir.ua.edu/handle/123456789/1063","outbound_label":"Repository record","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Paley, Mark S.","Shaughnessy, Kevin H.","Snowden, Timothy S.","Thrasher, Joseph S."]},{"key":"dc:contributor.advisor","label":"Advisor","values":["Jennings, Michael P."]},{"key":"dc:contributor.other","label":"Dc Contributor Other","values":["University of Alabama Tuscaloosa"]},{"key":"dc:creator","label":"Author","values":["Martinez, Dionicio Solorio"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2017-03-01T14:39:24Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2017-03-01T14:39:24Z"]},{"key":"dc:date.issued","label":"Date","values":["2011"]},{"key":"dc:publisher","label":"Institution","values":["University of Alabama Libraries"]},{"key":"dc:type","label":"Dc Type","values":["thesis","text"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Organic chemistry","Chemistry"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["English"]},{"key":"dc:language.iso","label":"Language (ISO)","values":["en_US"]},{"key":"dc:rights","label":"Dc Rights","values":["All rights reserved by the author unless otherwise indicated."]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["u0015_0000001_0000558","Martinez_alatus_0004D_10710"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://ir.ua.edu/handle/123456789/1063"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Electronic Thesis or Dissertation"]},{"key":"dc:description.abstract","label":"Abstract","values":["This dissertation highlights studies into the total synthesis of C-glycoside natural products via oxocarbenium cationic intermediates with a brief introduction given in the first chapter. The second chapter examines our approach to the first total synthesis and absolute configuration of the antibiotic (+)-bruguierol C. The key step is the diastereoselective capture of an in situ generated oxocarbenium cation via an intramolecular Marson-type Friedel-Crafts cyclization, which concomitantly generates the chiral quaternary center. The third chapter illustrates the formal syntheses of (+)-brussonol and (+)-abrotanone, attained in a convergent and concise manner, making these syntheses the shortest to date. The key step, as with (+)-bruguierol C, involves the diastereoselective capture of an in situ generated oxocarbenium cation via an intramolecular Marson-type Friedel-Crafts cyclization. A novel methodology that employs catalytic quantities of pyridinium tribromide (Py*Br3) in methanol to chemoselectively deprotect primary TBS ethers in the presence of a variety of other protecting groups and common functional groups is the subject of the fourth chapter. The formal synthesis of the unnatural (-)-neopeltolide core, whose natural antipode has been found to be extremely cytotoxic and has emerged as a promising anticancer lead is discussed in the fifth chapter. Efficient application of the Evans' protocol for the synthesis of 1,3-syn diols via an intramolecular hetero-Michael addition followed by reductive deprotection of the resulting benzylidene acetal allowed for swift access to the ä-lactone. Central to the synthetic approach is a tandem nucleophilic addition-diastereoselective axial reduction of an in situ generated oxocarbenium cation to construct the â-C-glycoside moiety of the neopeltolide core. The final chapter of this dissertation describes the total synthesis of the proposed structure of pochonin J, whose reported structure features a rare á-C-glycoside moiety embedded within a 14-membered macrolactone. Key steps of this convergent synthesis include a chemoselective Wacker oxidation, a stereoselective allylation of an oxocarbenium cation intermediate to assemble the á-C-glycoside fragment, and a ring-closing metathesis (RCM) reaction to forge the 14-membered macrolactone. During our studies directed towards its laboratory synthesis, it was found that the spectroscopic data of the synthesized compound does not correlate to the initially described natural product."]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["electronic"]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Syntheses of C-glycoside natural products via oxocarbenium cationic intermediates"]}]}],"canonical_facts":{"dc:contributor":["Paley, Mark S.","Shaughnessy, Kevin H.","Snowden, Timothy S.","Thrasher, Joseph S."],"dc:contributor.advisor":["Jennings, Michael P."],"dc:contributor.other":["University of Alabama Tuscaloosa"],"dc:creator":["Martinez, Dionicio Solorio"],"dc:date.accessioned":["2017-03-01T14:39:24Z"],"dc:date.available":["2017-03-01T14:39:24Z"],"dc:date.issued":["2011"],"dc:description":["Electronic Thesis or Dissertation"],"dc:description.abstract":["This dissertation highlights studies into the total synthesis of C-glycoside natural products via oxocarbenium cationic intermediates with a brief introduction given in the first chapter. The second chapter examines our approach to the first total synthesis and absolute configuration of the antibiotic (+)-bruguierol C. The key step is the diastereoselective capture of an in situ generated oxocarbenium cation via an intramolecular Marson-type Friedel-Crafts cyclization, which concomitantly generates the chiral quaternary center. The third chapter illustrates the formal syntheses of (+)-brussonol and (+)-abrotanone, attained in a convergent and concise manner, making these syntheses the shortest to date. The key step, as with (+)-bruguierol C, involves the diastereoselective capture of an in situ generated oxocarbenium cation via an intramolecular Marson-type Friedel-Crafts cyclization. A novel methodology that employs catalytic quantities of pyridinium tribromide (Py*Br3) in methanol to chemoselectively deprotect primary TBS ethers in the presence of a variety of other protecting groups and common functional groups is the subject of the fourth chapter. The formal synthesis of the unnatural (-)-neopeltolide core, whose natural antipode has been found to be extremely cytotoxic and has emerged as a promising anticancer lead is discussed in the fifth chapter. Efficient application of the Evans' protocol for the synthesis of 1,3-syn diols via an intramolecular hetero-Michael addition followed by reductive deprotection of the resulting benzylidene acetal allowed for swift access to the ä-lactone. Central to the synthetic approach is a tandem nucleophilic addition-diastereoselective axial reduction of an in situ generated oxocarbenium cation to construct the â-C-glycoside moiety of the neopeltolide core. The final chapter of this dissertation describes the total synthesis of the proposed structure of pochonin J, whose reported structure features a rare á-C-glycoside moiety embedded within a 14-membered macrolactone. Key steps of this convergent synthesis include a chemoselective Wacker oxidation, a stereoselective allylation of an oxocarbenium cation intermediate to assemble the á-C-glycoside fragment, and a ring-closing metathesis (RCM) reaction to forge the 14-membered macrolactone. During our studies directed towards its laboratory synthesis, it was found that the spectroscopic data of the synthesized compound does not correlate to the initially described natural product."],"dc:format.medium":["electronic"],"dc:format.mimetype":["application/pdf"],"dc:identifier.other":["u0015_0000001_0000558","Martinez_alatus_0004D_10710"],"dc:identifier.uri":["https://ir.ua.edu/handle/123456789/1063"],"dc:language":["English"],"dc:language.iso":["en_US"],"dc:publisher":["University of Alabama Libraries"],"dc:rights":["All rights reserved by the author unless otherwise indicated."],"dc:subject":["Organic chemistry","Chemistry"],"dc:title":["Syntheses of C-glycoside natural products via oxocarbenium cationic intermediates"],"dc:type":["thesis","text"]},"updated_at":"2026-07-27T18:44:23Z"}