Diastereocontrolled synthesis of hetero- and carbocycles via manganese(III) and copper(II): towards a novel prostaglandin total synthesis
<p>The prostaglandins are a unique family of natural products found in all mammalian life, including humans. Their biological significance is profound, and they are responsible for a vast array of bodily functions. This importance, coupled with their low concentration <em>in vivo</em&...
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| Format: | Thesis |
| Language: | English |
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2008
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| _version_ | 1797074200189468672 |
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| author | Docherty, P Dr. Paul H. Docherty |
| author2 | Burton, J |
| author_facet | Burton, J Docherty, P Dr. Paul H. Docherty |
| author_sort | Docherty, P |
| collection | OXFORD |
| description | <p>The prostaglandins are a unique family of natural products found in all mammalian life, including humans. Their biological significance is profound, and they are responsible for a vast array of bodily functions. This importance, coupled with their low concentration <em>in vivo</em>, has made them attractive targets for total chemical synthesis.</p> <p>The work herein describes synthetic efforts towards their synthesis using an oxidative radical cyclisation to construct the key [3.3.0]-bridged bicyclic lactone, from which the prostaglandin skeleton may be derived. Key to this was the development of manganese(III) acetate and copper(II) triflate as optimal reagents for this cyclisation of unsaturated malonate/malonic acid derivatives. To study this, several model substrates for this crucial cyclisation were synthesised, and their cyclisation analysed.</p> <p>Chapter 5 describes the design and synthesis of several model substrates containing malonate groups for the oxidative radical cyclisation. The results of the cyclisation with manganese(III) and various copper(II) salts influenced the design of the substrates, and led to the use of malonic acids as more effective substrates for the formation of [3.3.0]-bicyclic lactones. A catalytic process, in which atmospheric oxygen is the terminal oxidant was also developed.</p> <p>Chapter 6 describes the studies towards a total synthesis of the prostaglandin family. Two potential routes are followed, the first of which used a key asymmetric epoxidation to install asymmetry. A Suzuki coupling was used to deliver the desired diene required for the cyclisation substrate, which was successfully cyclised using manganese(III) acetate and copper(II) triflate, creating the desired [3.3.0]-bicyclic lactone in good yield and with excellent diastereomeric control. A second, shorter route to the same lactone was also developed, using a novel asymmetric deconjugative aldol condensation to establish asymmetry. Cyclisation of this analogous substrate was also successful, delivering the same lactone after olefin metathesis.</p> |
| first_indexed | 2024-03-06T23:32:49Z |
| format | Thesis |
| id | oxford-uuid:6ca5556a-3d2d-454a-abbd-0a3a269c5724 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T23:32:49Z |
| publishDate | 2008 |
| record_format | dspace |
| spelling | oxford-uuid:6ca5556a-3d2d-454a-abbd-0a3a269c57242022-03-26T19:12:21ZDiastereocontrolled synthesis of hetero- and carbocycles via manganese(III) and copper(II): towards a novel prostaglandin total synthesisThesishttp://purl.org/coar/resource_type/c_db06uuid:6ca5556a-3d2d-454a-abbd-0a3a269c5724Natural productsOrganic synthesisAsymmetric catalysisHeterocyclic chemistrySynthetic organic chemistryCatalysisOrganic chemistryEnglishOxford University Research Archive - Valet2008Docherty, PDr. Paul H. DochertyBurton, J<p>The prostaglandins are a unique family of natural products found in all mammalian life, including humans. Their biological significance is profound, and they are responsible for a vast array of bodily functions. This importance, coupled with their low concentration <em>in vivo</em>, has made them attractive targets for total chemical synthesis.</p> <p>The work herein describes synthetic efforts towards their synthesis using an oxidative radical cyclisation to construct the key [3.3.0]-bridged bicyclic lactone, from which the prostaglandin skeleton may be derived. Key to this was the development of manganese(III) acetate and copper(II) triflate as optimal reagents for this cyclisation of unsaturated malonate/malonic acid derivatives. To study this, several model substrates for this crucial cyclisation were synthesised, and their cyclisation analysed.</p> <p>Chapter 5 describes the design and synthesis of several model substrates containing malonate groups for the oxidative radical cyclisation. The results of the cyclisation with manganese(III) and various copper(II) salts influenced the design of the substrates, and led to the use of malonic acids as more effective substrates for the formation of [3.3.0]-bicyclic lactones. A catalytic process, in which atmospheric oxygen is the terminal oxidant was also developed.</p> <p>Chapter 6 describes the studies towards a total synthesis of the prostaglandin family. Two potential routes are followed, the first of which used a key asymmetric epoxidation to install asymmetry. A Suzuki coupling was used to deliver the desired diene required for the cyclisation substrate, which was successfully cyclised using manganese(III) acetate and copper(II) triflate, creating the desired [3.3.0]-bicyclic lactone in good yield and with excellent diastereomeric control. A second, shorter route to the same lactone was also developed, using a novel asymmetric deconjugative aldol condensation to establish asymmetry. Cyclisation of this analogous substrate was also successful, delivering the same lactone after olefin metathesis.</p> |
| spellingShingle | Natural products Organic synthesis Asymmetric catalysis Heterocyclic chemistry Synthetic organic chemistry Catalysis Organic chemistry Docherty, P Dr. Paul H. Docherty Diastereocontrolled synthesis of hetero- and carbocycles via manganese(III) and copper(II): towards a novel prostaglandin total synthesis |
| title | Diastereocontrolled synthesis of hetero- and carbocycles via manganese(III) and copper(II): towards a novel prostaglandin total synthesis |
| title_full | Diastereocontrolled synthesis of hetero- and carbocycles via manganese(III) and copper(II): towards a novel prostaglandin total synthesis |
| title_fullStr | Diastereocontrolled synthesis of hetero- and carbocycles via manganese(III) and copper(II): towards a novel prostaglandin total synthesis |
| title_full_unstemmed | Diastereocontrolled synthesis of hetero- and carbocycles via manganese(III) and copper(II): towards a novel prostaglandin total synthesis |
| title_short | Diastereocontrolled synthesis of hetero- and carbocycles via manganese(III) and copper(II): towards a novel prostaglandin total synthesis |
| title_sort | diastereocontrolled synthesis of hetero and carbocycles via manganese iii and copper ii towards a novel prostaglandin total synthesis |
| topic | Natural products Organic synthesis Asymmetric catalysis Heterocyclic chemistry Synthetic organic chemistry Catalysis Organic chemistry |
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