{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/109613"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/109613","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"I. Total synthesis of sesquiterpene-tropolones II. Dearomative hydroamination and application to the synthesis of aminoglycosides","abstract":"The student, Chad Ungarean, accepted the attached license on 2020-12-01 at 04:52.","abstract_html":"The student, Chad Ungarean, accepted the attached license on 2020-12-01 at 04:52.","abstract_has_math":false,"creators":["Ungarean, Chad Nicholas"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Chemistry","degree_department":null,"school":null,"contributors":["Sarlah, David","Denmark, Scott E","White, M. Christina","Silverman, Scott K"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2021,"date_issued":"2021-03-05T21:45:41Z","date_published":"2021-03-05T21:45:41Z","updated_at":"2026-07-22T22:24:50Z","subjects":["Total synthesis","sequiterpenes","hydroamination","aminoglycosides"],"languages":["en"],"rights":["Copyright 2020 Chad Ungarean"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/109613","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Sarlah, David","Denmark, Scott E","White, M. Christina","Silverman, Scott K"]},{"key":"dc:creator","label":"Author","values":["Ungarean, Chad Nicholas"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2021-03-05T21:45:41Z","2023-03-05T21:47:41Z","2020-12-03","2020-12"]},{"key":"dc:type","label":"Dc Type","values":["text","Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Chemistry"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Total synthesis","sequiterpenes","hydroamination","aminoglycosides"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2020 Chad Ungarean"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/109613"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["The student, Chad Ungarean, accepted the attached license on 2020-12-01 at 04:52.","The student, Chad Ungarean, submitted this Dissertation for approval on 2020-12-01 at 05:14.","This Dissertation was approved for publication on 2020-12-03 at 14:52.","DSpace SAF Submission Ingestion Package generated from Vireo submission #16005 on 2021-03-04 at 16:32:46","Made available in DSpace on 2021-03-05T21:45:41Z (GMT). No. of bitstreams: 2 UNGAREAN-DISSERTATION-2020.pdf: 16715862 bytes, checksum: d1db13bb778108df48012227716bbc50 (MD5) LICENSE.txt: 4210 bytes, checksum: 2fd70024e8cf85c29c740b916272ecf1 (MD5) Previous issue date: 2020-12-03","The first chapter discusses the development of a platform for the synthesis of a variety of bioactive sesquiterpene-tropolones. The synthetic strategy relies on the union of key fragments via an inverse electron demand hetero-Diels–Alder (HDA) reaction between either humulene or humulene derivatives and a tropolone ortho-quinone methide (o-QM). Tropolone construction utilizes [2+2] cycloaddition of a linear precursor followed by either de Mayo type or photochemical fragmentation approaches to arrive at the requisite o-QM precursor. The 10-hydroxy-–humulene component relies on a semi-synthetic route starting from caryophyllene oxide and utilizing a key HAT ring expansion to arrive at the 11-membered macrocycle. The culmination of these synthetic efforts has elucidated a reasonable biosynthesis of the pycnidione series along with the structural reassignment of several members of the class. Additionally, the synthesis of unnatural epi,epi- and epi,ent-pycnidione has been enabled. Current focus is on the construction of a library of analogs as well as the biological evaluation of these compounds. The second chapter details the development of a dearomative hydroamination methodology of simple arenes. This novel reaction was extended to several mono- and polynuclear arenes and heteroarenes. Utilizing benzene as a starting material, a divergent synthetic strategy was executed to arrive as the 2-deoxystreptamine (2-DOS) and 2-deoxyfortamine (2-DOF) aminoglycoside cores; key synthetic steps in the 2-DOS and 2-DOF cores include a 5-exo-tet cyclization and bromonium induced rearrangement. Furthermore, from these scaffolds, the synthesis of ribostamycin and istamycin have been pursued and are in the final stages of construction. Current efforts involve the global deprotection of the penultimate intermediate for ribostamycin as well as glycosylation and global deprotection for istamycin. Additionally, the synthesis of unnatural analogs is underway.","Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2022-12-01","Embargo set by: Seth Robbins for item 117318 Lift date: 2023-03-05T21:45:47Z Reason: Author requested closed access (OA after 2yrs) in Vireo ETD system","Embargo set by: Seth Robbins for item 117318 Lift date: 2023-03-05T21:47:41Z Reason: Author requested closed access (OA after 2yrs) in Vireo ETD system","Author requested closed access (OA after 2yrs) in Vireo ETD system","Limited"]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["I. Total synthesis of sesquiterpene-tropolones II. Dearomative hydroamination and application to the synthesis of aminoglycosides"]}]}],"canonical_facts":{"dc:contributor":["Sarlah, David","Denmark, Scott E","White, M. Christina","Silverman, Scott K"],"dc:creator":["Ungarean, Chad Nicholas"],"dc:date":["2021-03-05T21:45:41Z","2023-03-05T21:47:41Z","2020-12-03","2020-12"],"dc:description":["The student, Chad Ungarean, accepted the attached license on 2020-12-01 at 04:52.","The student, Chad Ungarean, submitted this Dissertation for approval on 2020-12-01 at 05:14.","This Dissertation was approved for publication on 2020-12-03 at 14:52.","DSpace SAF Submission Ingestion Package generated from Vireo submission #16005 on 2021-03-04 at 16:32:46","Made available in DSpace on 2021-03-05T21:45:41Z (GMT). No. of bitstreams: 2 UNGAREAN-DISSERTATION-2020.pdf: 16715862 bytes, checksum: d1db13bb778108df48012227716bbc50 (MD5) LICENSE.txt: 4210 bytes, checksum: 2fd70024e8cf85c29c740b916272ecf1 (MD5) Previous issue date: 2020-12-03","The first chapter discusses the development of a platform for the synthesis of a variety of bioactive sesquiterpene-tropolones. The synthetic strategy relies on the union of key fragments via an inverse electron demand hetero-Diels–Alder (HDA) reaction between either humulene or humulene derivatives and a tropolone ortho-quinone methide (o-QM). Tropolone construction utilizes [2+2] cycloaddition of a linear precursor followed by either de Mayo type or photochemical fragmentation approaches to arrive at the requisite o-QM precursor. The 10-hydroxy-–humulene component relies on a semi-synthetic route starting from caryophyllene oxide and utilizing a key HAT ring expansion to arrive at the 11-membered macrocycle. The culmination of these synthetic efforts has elucidated a reasonable biosynthesis of the pycnidione series along with the structural reassignment of several members of the class. Additionally, the synthesis of unnatural epi,epi- and epi,ent-pycnidione has been enabled. Current focus is on the construction of a library of analogs as well as the biological evaluation of these compounds. The second chapter details the development of a dearomative hydroamination methodology of simple arenes. This novel reaction was extended to several mono- and polynuclear arenes and heteroarenes. Utilizing benzene as a starting material, a divergent synthetic strategy was executed to arrive as the 2-deoxystreptamine (2-DOS) and 2-deoxyfortamine (2-DOF) aminoglycoside cores; key synthetic steps in the 2-DOS and 2-DOF cores include a 5-exo-tet cyclization and bromonium induced rearrangement. Furthermore, from these scaffolds, the synthesis of ribostamycin and istamycin have been pursued and are in the final stages of construction. Current efforts involve the global deprotection of the penultimate intermediate for ribostamycin as well as glycosylation and global deprotection for istamycin. Additionally, the synthesis of unnatural analogs is underway.","Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2022-12-01","Embargo set by: Seth Robbins for item 117318 Lift date: 2023-03-05T21:45:47Z Reason: Author requested closed access (OA after 2yrs) in Vireo ETD system","Embargo set by: Seth Robbins for item 117318 Lift date: 2023-03-05T21:47:41Z Reason: Author requested closed access (OA after 2yrs) in Vireo ETD system","Author requested closed access (OA after 2yrs) in Vireo ETD system","Limited"],"dc:format":["application/pdf"],"dc:identifier":["http://hdl.handle.net/2142/109613"],"dc:language":["en"],"dc:rights":["Copyright 2020 Chad Ungarean"],"dc:subject":["Total synthesis","sequiterpenes","hydroamination","aminoglycosides"],"dc:title":["I. Total synthesis of sesquiterpene-tropolones II. Dearomative hydroamination and application to the synthesis of aminoglycosides"],"dc:type":["text","Thesis"],"thesis:degree_discipline":["Chemistry"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:24:50Z"}