{"id":{"repo_id":"oldenburg","oai_identifier":"oai:oops.uni-oldenburg.de:741"},"canonical_url":"https://search.dev.ndltd.org/etd/oldenburg/oai:oops.uni-oldenburg.de:741","repository":{"repo_id":"oldenburg","name":"Carl von Ossietzky Universität Oldenburg","base_url":"http://oops.uni-oldenburg.de/cgi/oai2"},"display":{"title":"Synthetic studies on Canangone and beta-Chamigrene","abstract":"The objective of this work was to synthesize the quaternary stereocenter containing spirocycles, (+)-Canangone and beta-Chamigrene. Michael acceptor was prepared in three steps. The Robinson annulation of enamino lactone and Michael acceptor followed by hydrolysis provided the spirolactone. Subsequent deprotection, Luche reduction and oxidation gave (R*,R*) Canangone and (5R*,6S*)-epi-Canangone. Following the same strategy, optically active (+)-Canangone and (-)-Canangone, and their epimers were synthesized. As a second target, the synthesis of -Chamigrene was attempted but unfortunately, attempts to synthesize the -Chamigrene precursor completely failed.An alternative route was proposed, in which -Chamigrene could be synthesized in only four steps. The Diels-Alder reaction of methyl vinyl ketone and isoprene gave acetyl cyclohexene and alkylation of this product using prenyl iodide provided the mono alkylated product but unfortunately, attempts to cyclize it failed completely to give the desired spirocyclic compound.","abstract_html":"The objective of this work was to synthesize the quaternary stereocenter containing spirocycles, (+)-Canangone and beta-Chamigrene. Michael acceptor was prepared in three steps. The Robinson annulation of enamino lactone and Michael acceptor followed by hydrolysis provided the spirolactone. Subsequent deprotection, Luche reduction and oxidation gave (R*,R*) Canangone and (5R*,6S*)-epi-Canangone. Following the same strategy, optically active (+)-Canangone and (-)-Canangone, and their epimers were synthesized. As a second target, the synthesis of -Chamigrene was attempted but unfortunately, attempts to synthesize the -Chamigrene precursor completely failed.An alternative route was proposed, in which -Chamigrene could be synthesized in only four steps. The Diels-Alder reaction of methyl vinyl ketone and isoprene gave acetyl cyclohexene and alkylation of this product using prenyl iodide provided the mono alkylated product but unfortunately, attempts to cyclize it failed completely to give the desired spirocyclic compound.","abstract_has_math":false,"creators":["Koripelly, Girish Kumar"],"institution":"Universität Oldenburg","degree_name":null,"degree_level":"thesis.doctoral","degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2008,"date_issued":"2008-02-04","date_published":"2008-02-04","updated_at":"2026-07-27T20:27:42Z","subjects":["[Keine Schlagwörter von Autor/in vergeben.]"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://oops.uni-oldenburg.de/741","outbound_label":"Repository record","outbound_source":"source_url"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Koripelly, Girish Kumar"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:publisher","label":"Institution","values":["BIS der Universität Oldenburg"]},{"key":"dc:type","label":"Dc Type","values":["doctoralThesis"]},{"key":"thesis:degree_level","label":"Degree Level","values":["thesis.doctoral"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Universität Oldenburg"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["[Keine Schlagwörter von Autor/in vergeben.]"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The objective of this work was to synthesize the quaternary stereocenter containing spirocycles, (+)-Canangone and beta-Chamigrene. Michael acceptor was prepared in three steps. The Robinson annulation of enamino lactone and Michael acceptor followed by hydrolysis provided the spirolactone. Subsequent deprotection, Luche reduction and oxidation gave (R*,R*) Canangone and (5R*,6S*)-epi-Canangone. Following the same strategy, optically active (+)-Canangone and (-)-Canangone, and their epimers were synthesized. As a second target, the synthesis of -Chamigrene was attempted but unfortunately, attempts to synthesize the -Chamigrene precursor completely failed.An alternative route was proposed, in which -Chamigrene could be synthesized in only four steps. The Diels-Alder reaction of methyl vinyl ketone and isoprene gave acetyl cyclohexene and alkylation of this product using prenyl iodide provided the mono alkylated product but unfortunately, attempts to cyclize it failed completely to give the desired spirocyclic compound.","Das Ziel dieser Arbeit war die Synthese zweier Verbindungen mit quartären Stereozentren, (+)-Canangon und beta-Chamigren. Ausgehend von den Verbindungen 3,4 Dimethoxybenzylalkohol und Bromessigsäure wurde in drei Stufen via Williamsonsche Ethersynthese, Aminolyse und Grignardaddition dargestellt. Spirolacton wurde durch eine Robinson-Anellierung des Enaminlactons mit dem Michaelakzeptor synthetisiert. Nach dem Entschützen wurde das Enon zu den beiden diastereoisomeren Alkoholen reduziert. Schlielich wurden diese selektiv mit O2 zu (R*,R*)-Canangon und (5R*,6S*)-epi-Canangon oxidiert. Um nun das zweite Syntheseziel, beta-Chamigren, zu erhalten, wurden zwei unterschiedliche Ansätze verfolgt. Nach einer sollte beta-Chamigren in nur vier Stufen zugänglich sein. Eine Lewis-Säure-katalysierte Diels-Alder-Reaktion von Methylvinylketon mit Isopren ergab ein Cyclohexen. Die Umsetzung mit Prenyliodid führte daraufhin glatt zur monoalkylierten Verbindung, welche sich allerdings nicht mehr weiter zur spirocyclischen Vorstufe cyclisieren ließ."]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Synthetic studies on Canangone and beta-Chamigrene"]}]}],"canonical_facts":{"dc:creator":["Koripelly, Girish Kumar"],"dc:description.abstract":["The objective of this work was to synthesize the quaternary stereocenter containing spirocycles, (+)-Canangone and beta-Chamigrene. Michael acceptor was prepared in three steps. The Robinson annulation of enamino lactone and Michael acceptor followed by hydrolysis provided the spirolactone. Subsequent deprotection, Luche reduction and oxidation gave (R*,R*) Canangone and (5R*,6S*)-epi-Canangone. Following the same strategy, optically active (+)-Canangone and (-)-Canangone, and their epimers were synthesized. As a second target, the synthesis of -Chamigrene was attempted but unfortunately, attempts to synthesize the -Chamigrene precursor completely failed.An alternative route was proposed, in which -Chamigrene could be synthesized in only four steps. The Diels-Alder reaction of methyl vinyl ketone and isoprene gave acetyl cyclohexene and alkylation of this product using prenyl iodide provided the mono alkylated product but unfortunately, attempts to cyclize it failed completely to give the desired spirocyclic compound.","Das Ziel dieser Arbeit war die Synthese zweier Verbindungen mit quartären Stereozentren, (+)-Canangon und beta-Chamigren. Ausgehend von den Verbindungen 3,4 Dimethoxybenzylalkohol und Bromessigsäure wurde in drei Stufen via Williamsonsche Ethersynthese, Aminolyse und Grignardaddition dargestellt. Spirolacton wurde durch eine Robinson-Anellierung des Enaminlactons mit dem Michaelakzeptor synthetisiert. Nach dem Entschützen wurde das Enon zu den beiden diastereoisomeren Alkoholen reduziert. Schlielich wurden diese selektiv mit O2 zu (R*,R*)-Canangon und (5R*,6S*)-epi-Canangon oxidiert. Um nun das zweite Syntheseziel, beta-Chamigren, zu erhalten, wurden zwei unterschiedliche Ansätze verfolgt. Nach einer sollte beta-Chamigren in nur vier Stufen zugänglich sein. Eine Lewis-Säure-katalysierte Diels-Alder-Reaktion von Methylvinylketon mit Isopren ergab ein Cyclohexen. Die Umsetzung mit Prenyliodid führte daraufhin glatt zur monoalkylierten Verbindung, welche sich allerdings nicht mehr weiter zur spirocyclischen Vorstufe cyclisieren ließ."],"dc:format.medium":["application/pdf"],"dc:publisher":["BIS der Universität Oldenburg"],"dc:subject":["[Keine Schlagwörter von Autor/in vergeben.]"],"dc:title":["Synthetic studies on Canangone and beta-Chamigrene"],"dc:type":["doctoralThesis"],"thesis:degree_level":["thesis.doctoral"],"thesis:institution_name":["Universität Oldenburg"]},"updated_at":"2026-07-27T20:27:42Z"}