{"id":{"repo_id":"aachen","oai_identifier":"oai:publications.rwth-aachen.de:52361"},"canonical_url":"https://search.dev.ndltd.org/etd/aachen/oai:publications.rwth-aachen.de:52361","repository":{"repo_id":"aachen","name":"RWTH Aachen University","base_url":"https://publications.rwth-aachen.de/oai2d"},"display":{"title":"Asymmetrische Synthese von Sordidin, 7-epi-Sordidin und von Polyoeinheiten mit quartären Stereozentren","abstract":"Pheromones have become very important in phytosanitary strategies. Within the thesis the first asymmetric synthesis of (+)-sordidin and (-)-7-epi-sordidin, aggregation pheromones of the banana weevil Cosmopolites sordidus which is the most important world-wide insect pest of banana plants has been achieved. Starting from dioxanone RAMP-hydrazone the desired C-7 epimers were prepared in 39% overall yield as a 1.5: 1 diastereomeric mixture over 14 steps. The epimers could be separated by preparative GC and thus, each of them could be obtained in high diastereomeric and enantiomeric purity (de > 97%, ee > 98%). Their NMR spectroscopic data and optical rotation values are consistent with those given in the literature. Furthermore, a synthesis strategy towards alpha,alpha´-quaternary, alpha,alpha´-dimethylated 2-keto-1,3-diols could be developed. This characteristic structural feature could be found in several biologically active natural products such as anisatin which proved to be a potent neurotoxin. In addition, staminol A which was isolated from the Vietnamese medical plant called Orthosiphon stamineus BENTH. and is used in treating jaundice, rheumatism, hepatitis, influenca and colon carcinoma as well as citreoviral, a specific inhibitor for mitochondrial therapy belong to this class of substrat. Within this thesis these diverse substituted alpha, alpha´-quatenary 2-keto-1,3-diols could be generated starting from easily available dioxanone SAMP-hydrazone in 14-61% yield over five steps. The protocol included 4 consecutive and diastereoselective alpha-alkylation steps, thereof two alpha-quaternarisation steps, the last one carried out in the presence of DMPU, employing the SAMP/RAMP-hydrazone methodology developed by Enders et al. After subsequent acidic cleavage of both the chiral auxiliary and the acetal moiety these 2-keto-1,3-diols bearing two quaternary stereocenters could be obtained with high stereoselectivity (de > 79-97%, ee > 96-99%). Additionally, a diastereo- and enantioselective access to 1,2-quaternary, 1,3-protected 1,2,3-triols was achieved via substituent-controlled nucleophilic 1,2-addition to the carbonyl group of the dioxanone system. Another essential part of the thesis was focused on the synthesis of a mono-protected sugar unit called 4´-epi-2-C-methyl-D-5-deoxyribose whose unprotected C-4 epimer could be found as an unusual sugar in trachycladine A and B. Both were isolated from a marine sponge Trachycladus laevispirulifer which thrives in the gulf of Exmouth in Western Australia and belong to the class of nucleosides. In recent tests trachycladine A showed in vitro cytotoxicity against sevaral cell lines including leukaemia, colon and breast tumors. Again starting from dioxanone SAMP-hydrazone the synthesis of the MOM-protected 4´-epi-2-C-methyl-D-5-deoxyribose could be completed in nine steps providing an anomeric mixture (dr = 3:1) in 35% overall yield. Further, the TBS-protected precursor of 4´-epi-2-C-methyl-D-5-deoxyribose was synthesized over 8 steps in 47% yield. A subsequent coupling of the lactols towards the corresponding purine bases, hypoxanthine and chloroadenine applying the Vorbrüggen protocol should – after deprotection of the hydroxyl function – result in 4´-epi trachycladine A and B.","abstract_html":"Pheromones have become very important in phytosanitary strategies. Within the thesis the first asymmetric synthesis of (+)-sordidin and (-)-7-epi-sordidin, aggregation pheromones of the banana weevil Cosmopolites sordidus which is the most important world-wide insect pest of banana plants has been achieved. Starting from dioxanone RAMP-hydrazone the desired C-7 epimers were prepared in 39% overall yield as a 1.5: 1 diastereomeric mixture over 14 steps. The epimers could be separated by preparative GC and thus, each of them could be obtained in high diastereomeric and enantiomeric purity (de > 97%, ee > 98%). Their NMR spectroscopic data and optical rotation values are consistent with those given in the literature. Furthermore, a synthesis strategy towards alpha,alpha´-quaternary, alpha,alpha´-dimethylated 2-keto-1,3-diols could be developed. This characteristic structural feature could be found in several biologically active natural products such as anisatin which proved to be a potent neurotoxin. In addition, staminol A which was isolated from the Vietnamese medical plant called Orthosiphon stamineus BENTH. and is used in treating jaundice, rheumatism, hepatitis, influenca and colon carcinoma as well as citreoviral, a specific inhibitor for mitochondrial therapy belong to this class of substrat. Within this thesis these diverse substituted alpha, alpha´-quatenary 2-keto-1,3-diols could be generated starting from easily available dioxanone SAMP-hydrazone in 14-61% yield over five steps. The protocol included 4 consecutive and diastereoselective alpha-alkylation steps, thereof two alpha-quaternarisation steps, the last one carried out in the presence of DMPU, employing the SAMP/RAMP-hydrazone methodology developed by Enders et al. After subsequent acidic cleavage of both the chiral auxiliary and the acetal moiety these 2-keto-1,3-diols bearing two quaternary stereocenters could be obtained with high stereoselectivity (de > 79-97%, ee > 96-99%). Additionally, a diastereo- and enantioselective access to 1,2-quaternary, 1,3-protected 1,2,3-triols was achieved via substituent-controlled nucleophilic 1,2-addition to the carbonyl group of the dioxanone system. Another essential part of the thesis was focused on the synthesis of a mono-protected sugar unit called 4´-epi-2-C-methyl-D-5-deoxyribose whose unprotected C-4 epimer could be found as an unusual sugar in trachycladine A and B. Both were isolated from a marine sponge Trachycladus laevispirulifer which thrives in the gulf of Exmouth in Western Australia and belong to the class of nucleosides. In recent tests trachycladine A showed in vitro cytotoxicity against sevaral cell lines including leukaemia, colon and breast tumors. Again starting from dioxanone SAMP-hydrazone the synthesis of the MOM-protected 4´-epi-2-C-methyl-D-5-deoxyribose could be completed in nine steps providing an anomeric mixture (dr = 3:1) in 35% overall yield. Further, the TBS-protected precursor of 4´-epi-2-C-methyl-D-5-deoxyribose was synthesized over 8 steps in 47% yield. A subsequent coupling of the lactols towards the corresponding purine bases, hypoxanthine and chloroadenine applying the Vorbrüggen protocol should – after deprotection of the hydroxyl function – result in 4´-epi trachycladine A and B.","abstract_has_math":false,"creators":["Breuer, Irene"],"institution":"Mainz","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":["Enders, Dieter"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2005,"date_issued":"2005","date_published":"2005","updated_at":"2026-07-30T19:40:50Z","subjects":["info:eu-repo/classification/ddc/540","Sordidin","Polyole","Asymmetrische Synthese","Hydrazon-Methode","Quaternisierung","Chemie","quartäre Stereozentren","Trachycladin A","Trachycladin B","SAMP/RAMP-Hydrazon-Methode"],"languages":["ger"],"rights":["info:eu-repo/semantics/openAccess"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-114590%22"],"render_values":[{"text":"https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-114590%22","href":"https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-114590%22","code":true}]}]},"links":{"outbound_url":"https://publications.rwth-aachen.de/record/52361","outbound_label":"Repository record","outbound_source":"dc:identifier"},"source_record":{"url":"https://publications.rwth-aachen.de/oai2d?verb=GetRecord&metadataPrefix=oai_dc&identifier=oai%3Apublications.rwth-aachen.de%3A52361","prefix":"oai_dc"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Enders, Dieter"]},{"key":"dc:creator","label":"Author","values":["Breuer, Irene"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:coverage","label":"Dc Coverage","values":["DE"]},{"key":"dc:date","label":"Dc Date","values":["2005"]},{"key":"dc:publisher","label":"Institution","values":["Mainz"]},{"key":"dc:relation","label":"Dc Relation","values":["info:eu-repo/semantics/altIdentifier/urn/urn:nbn:de:hbz:82-opus-12342","info:eu-repo/semantics/altIdentifier/isbn/3-86130-548-8"]},{"key":"dc:type","label":"Dc Type","values":["info:eu-repo/semantics/doctoralThesis","info:eu-repo/semantics/publishedVersion"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["info:eu-repo/classification/ddc/540","Sordidin","Polyole","Asymmetrische Synthese","Hydrazon-Methode","Quaternisierung","Chemie","quartäre Stereozentren","Trachycladin A","Trachycladin B","SAMP/RAMP-Hydrazon-Methode"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["ger"]},{"key":"dc:rights","label":"Dc Rights","values":["info:eu-repo/semantics/openAccess"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://publications.rwth-aachen.de/record/52361","https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-114590%22"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Pheromones have become very important in phytosanitary strategies. Within the thesis the first asymmetric synthesis of (+)-sordidin and (-)-7-epi-sordidin, aggregation pheromones of the banana weevil Cosmopolites sordidus which is the most important world-wide insect pest of banana plants has been achieved. Starting from dioxanone RAMP-hydrazone the desired C-7 epimers were prepared in 39% overall yield as a 1.5: 1 diastereomeric mixture over 14 steps. The epimers could be separated by preparative GC and thus, each of them could be obtained in high diastereomeric and enantiomeric purity (de > 97%, ee > 98%). Their NMR spectroscopic data and optical rotation values are consistent with those given in the literature. Furthermore, a synthesis strategy towards alpha,alpha´-quaternary, alpha,alpha´-dimethylated 2-keto-1,3-diols could be developed. This characteristic structural feature could be found in several biologically active natural products such as anisatin which proved to be a potent neurotoxin. In addition, staminol A which was isolated from the Vietnamese medical plant called Orthosiphon stamineus BENTH. and is used in treating jaundice, rheumatism, hepatitis, influenca and colon carcinoma as well as citreoviral, a specific inhibitor for mitochondrial therapy belong to this class of substrat. Within this thesis these diverse substituted alpha, alpha´-quatenary 2-keto-1,3-diols could be generated starting from easily available dioxanone SAMP-hydrazone in 14-61% yield over five steps. The protocol included 4 consecutive and diastereoselective alpha-alkylation steps, thereof two alpha-quaternarisation steps, the last one carried out in the presence of DMPU, employing the SAMP/RAMP-hydrazone methodology developed by Enders et al. After subsequent acidic cleavage of both the chiral auxiliary and the acetal moiety these 2-keto-1,3-diols bearing two quaternary stereocenters could be obtained with high stereoselectivity (de > 79-97%, ee > 96-99%). Additionally, a diastereo- and enantioselective access to 1,2-quaternary, 1,3-protected 1,2,3-triols was achieved via substituent-controlled nucleophilic 1,2-addition to the carbonyl group of the dioxanone system. Another essential part of the thesis was focused on the synthesis of a mono-protected sugar unit called 4´-epi-2-C-methyl-D-5-deoxyribose whose unprotected C-4 epimer could be found as an unusual sugar in trachycladine A and B. Both were isolated from a marine sponge Trachycladus laevispirulifer which thrives in the gulf of Exmouth in Western Australia and belong to the class of nucleosides. In recent tests trachycladine A showed in vitro cytotoxicity against sevaral cell lines including leukaemia, colon and breast tumors. Again starting from dioxanone SAMP-hydrazone the synthesis of the MOM-protected 4´-epi-2-C-methyl-D-5-deoxyribose could be completed in nine steps providing an anomeric mixture (dr = 3:1) in 35% overall yield. Further, the TBS-protected precursor of 4´-epi-2-C-methyl-D-5-deoxyribose was synthesized over 8 steps in 47% yield. A subsequent coupling of the lactols towards the corresponding purine bases, hypoxanthine and chloroadenine applying the Vorbrüggen protocol should – after deprotection of the hydroxyl function – result in 4´-epi trachycladine A and B."]},{"key":"dc:source","label":"Dc Source","values":["Aachen : Mainz, Aachener Beiträge zur Chemie 64, II, 235 S. : graph. Darst. (2005). = Zugl.: Aachen, Techn. Hochsch., Diss., 2005"]},{"key":"dc:title","label":"Title","values":["Asymmetrische Synthese von Sordidin, 7-epi-Sordidin und von Polyoeinheiten mit quartären Stereozentren"]}]}],"canonical_facts":{"dc:contributor":["Enders, Dieter"],"dc:coverage":["DE"],"dc:creator":["Breuer, Irene"],"dc:date":["2005"],"dc:description":["Pheromones have become very important in phytosanitary strategies. Within the thesis the first asymmetric synthesis of (+)-sordidin and (-)-7-epi-sordidin, aggregation pheromones of the banana weevil Cosmopolites sordidus which is the most important world-wide insect pest of banana plants has been achieved. Starting from dioxanone RAMP-hydrazone the desired C-7 epimers were prepared in 39% overall yield as a 1.5: 1 diastereomeric mixture over 14 steps. The epimers could be separated by preparative GC and thus, each of them could be obtained in high diastereomeric and enantiomeric purity (de > 97%, ee > 98%). Their NMR spectroscopic data and optical rotation values are consistent with those given in the literature. Furthermore, a synthesis strategy towards alpha,alpha´-quaternary, alpha,alpha´-dimethylated 2-keto-1,3-diols could be developed. This characteristic structural feature could be found in several biologically active natural products such as anisatin which proved to be a potent neurotoxin. In addition, staminol A which was isolated from the Vietnamese medical plant called Orthosiphon stamineus BENTH. and is used in treating jaundice, rheumatism, hepatitis, influenca and colon carcinoma as well as citreoviral, a specific inhibitor for mitochondrial therapy belong to this class of substrat. Within this thesis these diverse substituted alpha, alpha´-quatenary 2-keto-1,3-diols could be generated starting from easily available dioxanone SAMP-hydrazone in 14-61% yield over five steps. The protocol included 4 consecutive and diastereoselective alpha-alkylation steps, thereof two alpha-quaternarisation steps, the last one carried out in the presence of DMPU, employing the SAMP/RAMP-hydrazone methodology developed by Enders et al. After subsequent acidic cleavage of both the chiral auxiliary and the acetal moiety these 2-keto-1,3-diols bearing two quaternary stereocenters could be obtained with high stereoselectivity (de > 79-97%, ee > 96-99%). Additionally, a diastereo- and enantioselective access to 1,2-quaternary, 1,3-protected 1,2,3-triols was achieved via substituent-controlled nucleophilic 1,2-addition to the carbonyl group of the dioxanone system. Another essential part of the thesis was focused on the synthesis of a mono-protected sugar unit called 4´-epi-2-C-methyl-D-5-deoxyribose whose unprotected C-4 epimer could be found as an unusual sugar in trachycladine A and B. Both were isolated from a marine sponge Trachycladus laevispirulifer which thrives in the gulf of Exmouth in Western Australia and belong to the class of nucleosides. In recent tests trachycladine A showed in vitro cytotoxicity against sevaral cell lines including leukaemia, colon and breast tumors. Again starting from dioxanone SAMP-hydrazone the synthesis of the MOM-protected 4´-epi-2-C-methyl-D-5-deoxyribose could be completed in nine steps providing an anomeric mixture (dr = 3:1) in 35% overall yield. Further, the TBS-protected precursor of 4´-epi-2-C-methyl-D-5-deoxyribose was synthesized over 8 steps in 47% yield. A subsequent coupling of the lactols towards the corresponding purine bases, hypoxanthine and chloroadenine applying the Vorbrüggen protocol should – after deprotection of the hydroxyl function – result in 4´-epi trachycladine A and B."],"dc:identifier":["https://publications.rwth-aachen.de/record/52361","https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-114590%22"],"dc:language":["ger"],"dc:publisher":["Mainz"],"dc:relation":["info:eu-repo/semantics/altIdentifier/urn/urn:nbn:de:hbz:82-opus-12342","info:eu-repo/semantics/altIdentifier/isbn/3-86130-548-8"],"dc:rights":["info:eu-repo/semantics/openAccess"],"dc:source":["Aachen : Mainz, Aachener Beiträge zur Chemie 64, II, 235 S. : graph. Darst. (2005). = Zugl.: Aachen, Techn. Hochsch., Diss., 2005"],"dc:subject":["info:eu-repo/classification/ddc/540","Sordidin","Polyole","Asymmetrische Synthese","Hydrazon-Methode","Quaternisierung","Chemie","quartäre Stereozentren","Trachycladin A","Trachycladin B","SAMP/RAMP-Hydrazon-Methode"],"dc:title":["Asymmetrische Synthese von Sordidin, 7-epi-Sordidin und von Polyoeinheiten mit quartären Stereozentren"],"dc:type":["info:eu-repo/semantics/doctoralThesis","info:eu-repo/semantics/publishedVersion"]},"updated_at":"2026-07-30T19:40:50Z"}