The accomplishment of the γ-alkylation reaction from β-keto esters of tropinone and the enantioselective aziridine formation from nortropinone is first reported. This opened two new paths to develop tropinone enolate chemistry. One is indirect α-alkylation of tropinone, another is the nucleophilic attack from α-C enolate to the nitrogen atom.<p>Seven interesting chiral amines have been synthesized and applied into the enolate chemistry of two interesting precursors of synthesis of natural products: 1,4-
cyclohexanedione monoethylene ketal and tropinone.<p>The aldol reaction between the lithium enolate of 1,4-cyclohexanedione monoethylene ketal and benzaldehyde demonstrated the high diastereoselectivity (up to 98% de) and the moderate to high enantioselectivity (up to 75% ee) induced by those chiral lithium amides. On the other hand, high diastereoselectivity (up to 100% de) and the low enantioselectivity were obtained from the aldol reaction of tropinone enolate with benzaldehyde differentiated by chiral lithium amides with extra electron donor atoms.<p>An analysis method to determine enantioselectivity from racemic α-hydroxytropinone was developed. That will, no doubt, benefit the further enantioselective α-hydroxylation reaction of tropinone.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:SSU.etd-10312007-165406 |
| Date | 03 December 2007 |
| Creators | Wang, Li |
| Contributors | Majewski, Marek |
| Publisher | University of Saskatchewan |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://library.usask.ca/theses/available/etd-10312007-165406/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University of Saskatchewan or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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