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|Title:||Broad-Spectrum Synthesis of Enantiomerically Pure Lactones|
|Author(s):||Adams, Paul Ernest|
|Department / Program:||Chemistry|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Abstract:||A general synthetic approach that affords both enantiomers of chiral lactones is described. The key step involves the automated multigram chromatography of diastereomeric derivatives of a racemic intermediate. The generality of the method is demonstrated by the synthesis of ring-saturated lactones of three different ring sizes, a series of bicyclic lactones, (alpha), (beta)-unsaturated lactones, and several examples containing aromatic substituents. Six of these examples occur in nature as pheromones or allomones, and hence are of biological interest. Assignments of absolute configuration to the lactone enantiomers and their precursors typically attend these syntheses. For some lactones, possessing suitable NMR spectra, direct determination of enantiomeric purity is possible using the chiral solvent (R)-(-)-2, 2, 2-trifluoro-1-(9-anthryl) ethanol.
The 1, 4-conjugate addition of organometallic reagents to chiral (alpha), (beta)-unsaturated lactones has been found to proceed with a very high degree of stereospecificity. This reaction, when coupled with the lactone resolution, affords a straightforward sequence for the introduction of chiral centers remote from functionality in high enantiomeric purity.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1980.
|Date Available in IDEALS:||2014-12-13|