Allylic hydroxy fatty compounds with Δ5-, Δ7-, Δ8-, and Δ10-Unsaturation

Oxidation reactions of acetylenic fatty esters with selenium dioxide/tert-butyl hydroperoxide

Reaction of methyl undec-10-ynoate (1) with selenium dioxide/tert-butyl hydroperoxide (TBHP) in aqueous dioxane gave methyl 9-oxo-undec-10-ynoate (2, 9%) and 9-hydroxy-undec-10-ynoate (3, 60%), while methyl octadec-9-ynoate (4) yielded mixtures of positional isomers of mono-keto (viz. methyl 8-oxo- and 11-oxo-octadec-9-ynoate, 5, 5%), hydroxy-keto (viz. methyl 8-hydroxy-11-oxo- and 11-hydroxy-8-oxo-octadec-9-ynoate, 6, 10%), and dihydroxy (viz. methyl 8,11-dihydroxy-octadec-9-ynoate, 7, 24%) derivatives. Similar treatment of a conjugated diacetylenic fatty ester (methyl octadeca-6,8-diynoate, 8) furnished a mixture of methyl 5-oxo- and 10-oxo-octadeca-6,8-diynoate (9, 12%) and a complex mixture of very polar products. Reaction of methyl octadec-11E-en-9-ynoate (methyl santalbate) (10) with selenium dioxide/TBHP in aqueous dioxane gave exclusively a mixture of regiospecific products, viz. methyl 8-oxo-octadec-11(E)Z-en-9-ynoate (11, 6%) and methyl 8-hydroxy-octadec-11E-en-9-ynoate (12, 70%). The structures of the various products were determined by a combination of spectroscopic and mass spectral analyses.

High-resolution nuclear magnetic resonance spectroscopy--applications to fatty acids and triacylglycerols

During the past two decades, nuclear magnetic resonance spectroscopy (NMR) has played an ever-increasing role in the structural determination of fatty acids, fatty acid derivatives and analogues, and in the analysis of the structures of triacylglycerols including the quantitative analysis of lipid mixtures. This article discusses some of the results obtained through the application of the NMR technique to lipid molecules and reviews the literature. To maintain brevity, this article does not cover the underlying theory of NMR spectroscopy as numerous books devoted to modern NMR spectroscopy have been published.