Studies on Pyridine n-oxides
<p>The work described herein is directed towards the Claisen rearrangements and [3+2] cycloaddition reaction of pyridine <em>N</em>-oxide systems. The pyridine <em>N</em>-oxide molecule is a very versatile and useful synthetic intermediate for the construction of more c...
| Main Authors: | , , |
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| Format: | Thesis |
| Language: | English |
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1995
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| _version_ | 1826297033946824704 |
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| author | Knott, J Harwood, L Knott, Jane |
| author2 | Harwood, L |
| author_facet | Harwood, L Knott, J Harwood, L Knott, Jane |
| author_sort | Knott, J |
| collection | OXFORD |
| description | <p>The work described herein is directed towards the Claisen rearrangements and [3+2] cycloaddition reaction of pyridine <em>N</em>-oxide systems. The pyridine <em>N</em>-oxide molecule is a very versatile and useful synthetic intermediate for the construction of more complex pyridines.</p><p>Chapter 1 contains a review of work carried out within the group towards Claisen rearrangement of benzene-type systems. The acid catalysed rearrangement of these systems affords a high degree of regioselectivity. A literature survey of the [3+2] cycloaddition reaction of both aliphatic nitrones and aromatic <em>N</em>-oxides with various dipolarophiles is also included. Access to many stereochemically pure products demonstrates that the [3+2] cycloaddition has become a very important ring-forming reaction.</p><p>Chapter 2 describes development of two Claisen rearrangement precursors and their subsequent attempted Claisen rearrangement is outlined.</p><p>Chapter 3 details the construction of a range of 3-substituted pyridine <em>N</em>-oxides. Their attempted intermolecular cycloaddition, by thermal means and at high pressure, with mono- and di-activated dipolarophiles is described.</p><p>Chapter 4 outlines attempts towards and the final synthesis of the ester cycloaddition precursors. Attempted intramolecular [3+2] cycloaddition of these substrates both thermally and under high pressure is summarised.</p><p>Chapter 5 describes approaches towards [3+2] cycloaddition precursors that contain mono- and di-activated dienophiles. The synthesis of a variety of 3-substituted pyridines is detailed.</p> |
| first_indexed | 2024-03-07T04:25:27Z |
| format | Thesis |
| id | oxford-uuid:cc74d06b-9840-4695-9f47-961583da147c |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T04:25:27Z |
| publishDate | 1995 |
| record_format | dspace |
| spelling | oxford-uuid:cc74d06b-9840-4695-9f47-961583da147c2022-03-27T07:22:08ZStudies on Pyridine n-oxidesThesishttp://purl.org/coar/resource_type/c_db06uuid:cc74d06b-9840-4695-9f47-961583da147cPyridineRing formation (Chemistry)SynthesisClaisen rearrangementDerivativesEnglishPolonsky Theses Digitisation Project1995Knott, JHarwood, LKnott, JaneHarwood, L<p>The work described herein is directed towards the Claisen rearrangements and [3+2] cycloaddition reaction of pyridine <em>N</em>-oxide systems. The pyridine <em>N</em>-oxide molecule is a very versatile and useful synthetic intermediate for the construction of more complex pyridines.</p><p>Chapter 1 contains a review of work carried out within the group towards Claisen rearrangement of benzene-type systems. The acid catalysed rearrangement of these systems affords a high degree of regioselectivity. A literature survey of the [3+2] cycloaddition reaction of both aliphatic nitrones and aromatic <em>N</em>-oxides with various dipolarophiles is also included. Access to many stereochemically pure products demonstrates that the [3+2] cycloaddition has become a very important ring-forming reaction.</p><p>Chapter 2 describes development of two Claisen rearrangement precursors and their subsequent attempted Claisen rearrangement is outlined.</p><p>Chapter 3 details the construction of a range of 3-substituted pyridine <em>N</em>-oxides. Their attempted intermolecular cycloaddition, by thermal means and at high pressure, with mono- and di-activated dipolarophiles is described.</p><p>Chapter 4 outlines attempts towards and the final synthesis of the ester cycloaddition precursors. Attempted intramolecular [3+2] cycloaddition of these substrates both thermally and under high pressure is summarised.</p><p>Chapter 5 describes approaches towards [3+2] cycloaddition precursors that contain mono- and di-activated dienophiles. The synthesis of a variety of 3-substituted pyridines is detailed.</p> |
| spellingShingle | Pyridine Ring formation (Chemistry) Synthesis Claisen rearrangement Derivatives Knott, J Harwood, L Knott, Jane Studies on Pyridine n-oxides |
| title | Studies on Pyridine n-oxides |
| title_full | Studies on Pyridine n-oxides |
| title_fullStr | Studies on Pyridine n-oxides |
| title_full_unstemmed | Studies on Pyridine n-oxides |
| title_short | Studies on Pyridine n-oxides |
| title_sort | studies on pyridine n oxides |
| topic | Pyridine Ring formation (Chemistry) Synthesis Claisen rearrangement Derivatives |
| work_keys_str_mv | AT knottj studiesonpyridinenoxides AT harwoodl studiesonpyridinenoxides AT knottjane studiesonpyridinenoxides |