Part one describes a systematic study of the diastereoselectivity of the Kinetic Michael addition of ester enolates to $\alpha$,$\beta$-unsaturated esters. Numerous examples of high selectivity have been discovered, and the factors that influence this selectivity were examined. The results are consistent with a chelated transition state. In most cases, there is a strong correlation between enolate geometry and the stereostructure of the adducts. By suitable modification of the substrate, excellent control over the stereoselectivity of the addition can often be achieved. Furthermore, the utility of the Michael intermediate has been developed and construction of several stereocenters by one synthetic operation has been achieved. / Part two describes a synthesis of the C$\sb3$-C$\sb{13}$ synthon of lonomycin A. A new tool for construction of the complex polypropionate-derived natural product was introduced. One of the prominent structural features in lonomycin is the repeating pattern of methyl and methoxyl substituents in the tetrahydrofuran and pyran rings of the molecule. The prospect of employing the Michael addition in an iterative fashion without being submerged in a myriad of diastereomers stood as one of the goals for the application of this methodology to the synthesis of complex structures. Stereoselective debromination of acyclic compounds has also been achieved. The union of the tetrahydropyran rings was accomplished through an aldol bond construction, and the factors controlling the stereoselective outcome were discussed. / Source: Dissertation Abstracts International, Volume: 52-10, Section: B, page: 5269. / Major Professor: Robert A. Holton. / Thesis (Ph.D.)--The Florida State University, 1991.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_76522 |
| Contributors | Jong, Ling., Florida State University |
| Source Sets | Florida State University |
| Language | English |
| Detected Language | English |
| Type | Text |
| Format | 610 p. |
| Rights | On campus use only. |
| Relation | Dissertation Abstracts International |
Page generated in 0.0016 seconds