{"id":{"repo_id":"east-anglia","oai_identifier":"oai:ueaeprints.uea.ac.uk:57413"},"canonical_url":"https://search.dev.ndltd.org/etd/east-anglia/oai:ueaeprints.uea.ac.uk:57413","repository":{"repo_id":"east-anglia","name":"University of East Anglia","base_url":"https://ueaeprints.uea.ac.uk/cgi/oai2"},"display":{"title":"Studies towards a total synthesis of Hippeastrine","abstract":"Tricarbonyl(ŋ5 -carboxylic acid methyl ester)iron(1+) hexafluorophosphate(1−) (97) was easily prepared in a moderate yield by a tandem Wittig-Michael addition using (3-methoxycarbonylallyl)triphenylphosphonium bromide (94). The resulting cyclohexa-1,3-dienecarboxylic acid methyl ester (95) was complexed with Fe2(CO)9 to obtain tricarbonyl(cyclohexa-1,3-dienecarboxylic acid methyl ester)iron(0) (96) was converted into the highly electrophilic tricarbonyl(ŋ5 -carboxylic acid methyl ester)iron(1+) hexafluorophosphate(1−) by hydride abstraction using triphenylcarbenium hexafluorophosphate (97). 4-Bromo-1,2-(methylenedioxy)benzene (132), 6-bromopiperonylic acid (98) and 2-bromo-5-methoxy benzoic acid (140) were converted into aryllithium reagents through lithiumbromide exchange by treatment with n-butyllithium. Lithiation and deuteration of 6-bromopiperonylic acid (98) , 2-bromobenzoic acid (136) and of 2-bromo-5-methoxybenzoic acid (140) were investigated by using various reagents such as n-butyllithium, LiHMDS and NaH to find the best route for the arylation of 98 to go onwards our target (+/−)-hippeastrine (107 and 108). Tricarbonyl[ŋ4-1-methyl ester-5-(3',4'-methylenedioxy)phenylcyclohexa- 1,3-diene]iron(0) (134) was prepared by preparing the aryllithium reagent 132 by lithium-bromide exchange and converting it into an organocuprate nucleophile with copper(I) bromide. Arylation with the cation 97 resulted in the formation of the complex 134. Tricarbonyl[ŋ4 -1-methyl ester-5- (3',4'-methylenedioxy-6'-carboxyphenyl)cyclohexa- 1,3-diene]iron(0) (99) was synthesised in the same way as complex (134), using the lithiated 6-bromopiperonylic acid (98) as the reagent. The structures of the compounds were determined by IR, 1HNMR, 13C-NMR spectroscopy and mass spectrometry.","abstract_html":"Tricarbonyl(ŋ5 -carboxylic acid methyl ester)iron(1+) hexafluorophosphate(1−) (97) was easily prepared in a moderate yield by a tandem Wittig-Michael addition using (3-methoxycarbonylallyl)triphenylphosphonium bromide (94). The resulting cyclohexa-1,3-dienecarboxylic acid methyl ester (95) was complexed with Fe2(CO)9 to obtain tricarbonyl(cyclohexa-1,3-dienecarboxylic acid methyl ester)iron(0) (96) was converted into the highly electrophilic tricarbonyl(ŋ5 -carboxylic acid methyl ester)iron(1+) hexafluorophosphate(1−) by hydride abstraction using triphenylcarbenium hexafluorophosphate (97). 4-Bromo-1,2-(methylenedioxy)benzene (132), 6-bromopiperonylic acid (98) and 2-bromo-5-methoxy benzoic acid (140) were converted into aryllithium reagents through lithiumbromide exchange by treatment with n-butyllithium. Lithiation and deuteration of 6-bromopiperonylic acid (98) , 2-bromobenzoic acid (136) and of 2-bromo-5-methoxybenzoic acid (140) were investigated by using various reagents such as n-butyllithium, LiHMDS and NaH to find the best route for the arylation of 98 to go onwards our target (+/−)-hippeastrine (107 and 108). Tricarbonyl[ŋ4-1-methyl ester-5-(3',4'-methylenedioxy)phenylcyclohexa- 1,3-diene]iron(0) (134) was prepared by preparing the aryllithium reagent 132 by lithium-bromide exchange and converting it into an organocuprate nucleophile with copper(I) bromide. Arylation with the cation 97 resulted in the formation of the complex 134. Tricarbonyl[ŋ4 -1-methyl ester-5- (3',4'-methylenedioxy-6'-carboxyphenyl)cyclohexa- 1,3-diene]iron(0) (99) was synthesised in the same way as complex (134), using the lithiated 6-bromopiperonylic acid (98) as the reagent. The structures of the compounds were determined by IR, 1HNMR, 13C-NMR spectroscopy and mass spectrometry.","abstract_has_math":false,"creators":["Helary, Johanna Myriam"],"institution":"University of East Anglia","degree_name":"phd","degree_level":"doctoral","degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2015,"date_issued":"2015-09","date_published":"2015-09","updated_at":"2026-07-24T02:12:13Z","subjects":[],"languages":["en"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":null,"outbound_label":null,"outbound_source":null},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Helary, Johanna Myriam"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2015-09"]},{"key":"dc:date.issued","label":"Date","values":["2015-09"]},{"key":"dc:publisher.department","label":"Dc Publisher Department","values":["School of Chemistry"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of East Anglia"]},{"key":"dc:relation.isreferencedby","label":"Dc Relation Isreferencedby","values":["https://ueaeprints.uea.ac.uk/id/eprint/57413/"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["doctoral"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["phd"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://ueaeprints.uea.ac.uk/id/eprint/57413/1/2015HelaryJMPhD.pdf"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Tricarbonyl(ŋ5 -carboxylic acid methyl ester)iron(1+) hexafluorophosphate(1−) (97) was easily prepared in a moderate yield by a tandem Wittig-Michael addition using (3-methoxycarbonylallyl)triphenylphosphonium bromide (94). The resulting cyclohexa-1,3-dienecarboxylic acid methyl ester (95) was complexed with Fe2(CO)9 to obtain tricarbonyl(cyclohexa-1,3-dienecarboxylic acid methyl ester)iron(0) (96) was converted into the highly electrophilic tricarbonyl(ŋ5 -carboxylic acid methyl ester)iron(1+) hexafluorophosphate(1−) by hydride abstraction using triphenylcarbenium hexafluorophosphate (97). 4-Bromo-1,2-(methylenedioxy)benzene (132), 6-bromopiperonylic acid (98) and 2-bromo-5-methoxy benzoic acid (140) were converted into aryllithium reagents through lithiumbromide exchange by treatment with n-butyllithium. Lithiation and deuteration of 6-bromopiperonylic acid (98) , 2-bromobenzoic acid (136) and of 2-bromo-5-methoxybenzoic acid (140) were investigated by using various reagents such as n-butyllithium, LiHMDS and NaH to find the best route for the arylation of 98 to go onwards our target (+/−)-hippeastrine (107 and 108). Tricarbonyl[ŋ4-1-methyl ester-5-(3',4'-methylenedioxy)phenylcyclohexa- 1,3-diene]iron(0) (134) was prepared by preparing the aryllithium reagent 132 by lithium-bromide exchange and converting it into an organocuprate nucleophile with copper(I) bromide. Arylation with the cation 97 resulted in the formation of the complex 134. Tricarbonyl[ŋ4 -1-methyl ester-5- (3',4'-methylenedioxy-6'-carboxyphenyl)cyclohexa- 1,3-diene]iron(0) (99) was synthesised in the same way as complex (134), using the lithiated 6-bromopiperonylic acid (98) as the reagent. The structures of the compounds were determined by IR, 1HNMR, 13C-NMR spectroscopy and mass spectrometry."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Studies towards a total synthesis of Hippeastrine"]}]}],"canonical_facts":{"dc:creator":["Helary, Johanna Myriam"],"dc:date":["2015-09"],"dc:date.issued":["2015-09"],"dc:description.abstract":["Tricarbonyl(ŋ5 -carboxylic acid methyl ester)iron(1+) hexafluorophosphate(1−) (97) was easily prepared in a moderate yield by a tandem Wittig-Michael addition using (3-methoxycarbonylallyl)triphenylphosphonium bromide (94). The resulting cyclohexa-1,3-dienecarboxylic acid methyl ester (95) was complexed with Fe2(CO)9 to obtain tricarbonyl(cyclohexa-1,3-dienecarboxylic acid methyl ester)iron(0) (96) was converted into the highly electrophilic tricarbonyl(ŋ5 -carboxylic acid methyl ester)iron(1+) hexafluorophosphate(1−) by hydride abstraction using triphenylcarbenium hexafluorophosphate (97). 4-Bromo-1,2-(methylenedioxy)benzene (132), 6-bromopiperonylic acid (98) and 2-bromo-5-methoxy benzoic acid (140) were converted into aryllithium reagents through lithiumbromide exchange by treatment with n-butyllithium. Lithiation and deuteration of 6-bromopiperonylic acid (98) , 2-bromobenzoic acid (136) and of 2-bromo-5-methoxybenzoic acid (140) were investigated by using various reagents such as n-butyllithium, LiHMDS and NaH to find the best route for the arylation of 98 to go onwards our target (+/−)-hippeastrine (107 and 108). Tricarbonyl[ŋ4-1-methyl ester-5-(3',4'-methylenedioxy)phenylcyclohexa- 1,3-diene]iron(0) (134) was prepared by preparing the aryllithium reagent 132 by lithium-bromide exchange and converting it into an organocuprate nucleophile with copper(I) bromide. Arylation with the cation 97 resulted in the formation of the complex 134. Tricarbonyl[ŋ4 -1-methyl ester-5- (3',4'-methylenedioxy-6'-carboxyphenyl)cyclohexa- 1,3-diene]iron(0) (99) was synthesised in the same way as complex (134), using the lithiated 6-bromopiperonylic acid (98) as the reagent. The structures of the compounds were determined by IR, 1HNMR, 13C-NMR spectroscopy and mass spectrometry."],"dc:format":["application/pdf"],"dc:identifier.uri":["https://ueaeprints.uea.ac.uk/id/eprint/57413/1/2015HelaryJMPhD.pdf"],"dc:language":["en"],"dc:publisher.department":["School of Chemistry"],"dc:publisher.institution":["University of East Anglia"],"dc:relation.isreferencedby":["https://ueaeprints.uea.ac.uk/id/eprint/57413/"],"dc:title":["Studies towards a total synthesis of Hippeastrine"],"dc:type":["Thesis"],"dc:type.qualificationlevel":["doctoral"],"dc:type.qualificationname":["phd"]},"updated_at":"2026-07-24T02:12:13Z"}