The Aza-Bohlmann cyclisation and the synthesis of Pandanus alkaloids
<p>Bohlmann et al. reported the oxidative spirocyclisation of 2-(ω-hydroxyalkyl)furans under Clauson-Kaas conditions to furnish 1,6-dioxaspiro[4.5]dec-3-enes, thereafter termed the “Bohlmann cyclisation.” This thesis describes the development of an analogous aza-Bohlmann cyclisation. Treatment...
| Prif Awduron: | , |
|---|---|
| Awduron Eraill: | |
| Fformat: | Traethawd Ymchwil |
| Iaith: | English |
| Cyhoeddwyd: |
2011
|
| Pynciau: |
| _version_ | 1826316154525712384 |
|---|---|
| author | Macnaughton, S Sarah Macnaughton |
| author2 | Robertson, J |
| author_facet | Robertson, J Macnaughton, S Sarah Macnaughton |
| author_sort | Macnaughton, S |
| collection | OXFORD |
| description | <p>Bohlmann et al. reported the oxidative spirocyclisation of 2-(ω-hydroxyalkyl)furans under Clauson-Kaas conditions to furnish 1,6-dioxaspiro[4.5]dec-3-enes, thereafter termed the “Bohlmann cyclisation.” This thesis describes the development of an analogous aza-Bohlmann cyclisation. Treatment of 2-(ω-aminoalkyl)furans with m-CPBA or singlet oxygen generates hydroxy- or methoxybutenolides, respectively, which undergo spirocyclisation upon treatment with H₂SO₄ to generate [4.4]- and [4.5]-spiroaminoacetals.</p><p>The axial/equatorial preferences of N-sulfonylspiroaminoacetals featuring a 3-O-isovaleryl or 3-O-benzyl substituent are described. Acid-catalysed equilibration revealed that in acetonitrile the axial isomer is thermodynamically favoured for both substrates.</p><p>The first total synthesis of the spiroaminoacetal alkaloid pandamarilactone-1 is discussed, via an aza-Bohlmann cyclisation, in 13 steps and 3% overall yield from 4-pentyn-1-ol.</p> |
| first_indexed | 2024-03-06T20:17:18Z |
| format | Thesis |
| id | oxford-uuid:2c91155f-0c0d-47b4-b8dc-f5e32fb2a8f9 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-12-09T03:38:45Z |
| publishDate | 2011 |
| record_format | dspace |
| spelling | oxford-uuid:2c91155f-0c0d-47b4-b8dc-f5e32fb2a8f92024-12-07T10:26:29ZThe Aza-Bohlmann cyclisation and the synthesis of Pandanus alkaloidsThesishttp://purl.org/coar/resource_type/c_db06uuid:2c91155f-0c0d-47b4-b8dc-f5e32fb2a8f9Heterocyclic chemistryNatural productsOrganic chemistryOrganic synthesisEnglishOxford University Research Archive - Valet2011Macnaughton, SSarah MacnaughtonRobertson, JDallimore, J<p>Bohlmann et al. reported the oxidative spirocyclisation of 2-(ω-hydroxyalkyl)furans under Clauson-Kaas conditions to furnish 1,6-dioxaspiro[4.5]dec-3-enes, thereafter termed the “Bohlmann cyclisation.” This thesis describes the development of an analogous aza-Bohlmann cyclisation. Treatment of 2-(ω-aminoalkyl)furans with m-CPBA or singlet oxygen generates hydroxy- or methoxybutenolides, respectively, which undergo spirocyclisation upon treatment with H₂SO₄ to generate [4.4]- and [4.5]-spiroaminoacetals.</p><p>The axial/equatorial preferences of N-sulfonylspiroaminoacetals featuring a 3-O-isovaleryl or 3-O-benzyl substituent are described. Acid-catalysed equilibration revealed that in acetonitrile the axial isomer is thermodynamically favoured for both substrates.</p><p>The first total synthesis of the spiroaminoacetal alkaloid pandamarilactone-1 is discussed, via an aza-Bohlmann cyclisation, in 13 steps and 3% overall yield from 4-pentyn-1-ol.</p> |
| spellingShingle | Heterocyclic chemistry Natural products Organic chemistry Organic synthesis Macnaughton, S Sarah Macnaughton The Aza-Bohlmann cyclisation and the synthesis of Pandanus alkaloids |
| title | The Aza-Bohlmann cyclisation and the synthesis of Pandanus alkaloids |
| title_full | The Aza-Bohlmann cyclisation and the synthesis of Pandanus alkaloids |
| title_fullStr | The Aza-Bohlmann cyclisation and the synthesis of Pandanus alkaloids |
| title_full_unstemmed | The Aza-Bohlmann cyclisation and the synthesis of Pandanus alkaloids |
| title_short | The Aza-Bohlmann cyclisation and the synthesis of Pandanus alkaloids |
| title_sort | aza bohlmann cyclisation and the synthesis of pandanus alkaloids |
| topic | Heterocyclic chemistry Natural products Organic chemistry Organic synthesis |
| work_keys_str_mv | AT macnaughtons theazabohlmanncyclisationandthesynthesisofpandanusalkaloids AT sarahmacnaughton theazabohlmanncyclisationandthesynthesisofpandanusalkaloids AT macnaughtons azabohlmanncyclisationandthesynthesisofpandanusalkaloids AT sarahmacnaughton azabohlmanncyclisationandthesynthesisofpandanusalkaloids |