Files in this item
|(no description provided)|
|Title:||Stereoselective Synthesis of Trisubstituted Olefins|
|Author(s):||Amburgey, Jack S.|
|Doctoral Committee Chair(s):||Denmark, Scott E.|
|Department / Program:||Chemistry|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Abstract:||A new method for the highly stereoselective synthesis of trisubstituted olefins is presented. The method involves the stereoselective construction of various $\beta$-hydroxy phosphonamidates followed by their thermolysis to provide trisubstituted olefins in extremely high geometrical purity ($>$99/1).
The stereoselective construction of $\beta$-hydroxy phosphonamidates could be accomplished through three main synthetic transformations. The first involves the acylation of various parent 1,3,2-oxazaphospholidines to provide monoalkylated $\beta$-keto phosphonamidates in good yield. The second step is the alkylation of the $\beta$-keto phosphonamidates to provide $\alpha,\alpha$-dialkylated $\beta$-keto phosphonamidates in high yield and very high diastereoselectivities. Finally, the highly diastereoselective reduction of the dialkylated $\beta$-keto phosphonamidates could be accomplished through the use of a variety of reducing agents to give $\beta$-hydroxy phosphonamidates in high yield and high diastereoselectivities.
Thermolysis of the diastereomerically pure $\beta$-hydroxy phosphonamidates gave a variety of trisubstituted olefins in high yield and very high stereoselectivity. A discussion on anionic mediated olefinations as well as an extension into the stereoselective synthesis of tetrasubstituted olefins is also presented.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1994.
|Date Available in IDEALS:||2014-12-17|