Part one describes a systematic study of the Michael addition of enolates to $\alpha,\beta$-unsaturated esters and thioesters. Numerous examples of high stereoselectivity have been discovered, and the factors that influence the stereoselection were examined. The use of the potassium enolate in the sequential Michael addition has been explored. Two consecutive Michael additions can be achieved with excellent diastereoselectivity. These results are consistent with a chelated transition state. Furthermore, asymmetric Michael additions of thioamide and ester enolates to chiral crotonates have been undertaken. Optically pure diastereomers were isolated by fractional recrystallization and the configuration of the Michael adducts were solved by single crystal X-ray crystallography and chemical correlations. / Part two describes a systematic study of the stereochemistry of the Michael addition of ester enolates to 3-alkoxy-2-bromoacrylates. The effects of the ether and ester alkyl substituents in the Michael acceptor and donor on the stereochemical outcome were investigated. These results are consistent with a chelated transition state. Asymmetric Michael additions utilizing chiral propionate ester enolates and methyl 2-bromo-3-methoxyacrylate have been carried out. A number of high asymmetric inductions were observed, and the factors controlling the facial selectivity were discussed. Optically pure Michael adducts were isolated and provided precursors for synthetic studies leading to Lonomycin A. / Source: Dissertation Abstracts International, Volume: 57-04, Section: B, page: 2574. / Major Professor: Robert A. Holton. / Thesis (Ph.D.)--The Florida State University, 1996.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_77719 |
| Contributors | Ren, Chien-Tai., Florida State University |
| Source Sets | Florida State University |
| Language | English |
| Detected Language | English |
| Type | Text |
| Format | 318 p. |
| Rights | On campus use only. |
| Relation | Dissertation Abstracts International |
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