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United States Department of Agriculture

Agricultural Research Service

Title: Nmr Characterization of Fatty Compounds Obtained Via Selenium Dioxide-Basedoxidations

Author
item Knothe, Gerhard

Submitted to: New Techniques and Applications for Lipid Analysis
Publication Type: Proceedings
Publication Acceptance Date: May 14, 1997
Publication Date: N/A

Technical Abstract: The reaction of monounsaturated fatty compounds with selenium dioxide in the presence of two reoxidants, tert. butylhydroperoxide (TBHP) and hydrogen peroxide, gives rise to novel fatty compounds. With TBHP as reoxidant, two allylic monohydroxy compounds and erythro/threo diastereomers of allylic dihydroxy compounds are obtained. The position of the allylic hydroxy group in allylic monohydroxy compounds can be determined by 1H and 13C NMR via shift differences. The erythro/threo diasteromers of the allylic dihydroxy acids can be distinguished by 1H NMR by means of shift differences to selected reference peaks and in 13C NMR by downfield shifts of the threo diastereomers. With H2O2 as reoxidant, novel intermediates, cyclic selenites, are obtained during vicinal dihydroxylation. The cyclic selenites, which exist as cis/trans isomers, were characterized by 1H, 13C, and 77Se NMR. The shift positions and differences of the olefinic carbons and shift differences of the olefinic protons in allylic monohydroxy fatty compounds can be described by either rational or logarithmic functions.

Last Modified: 8/22/2014
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