The general approach disclosed herein opens the new possibilities of exploiting the oxidation processes followed by chemiluminescence (CL) emission for the assessment of an antioxidant potential of natural lipid materials and enables determination of the amount and strength of lipid-borne antioxidants in one experiment. The reliability of the analytical procedure is completely unaffected by an inevitable entering of oxidizable lipid portions into the probe chemiluminescent mixture, which is exemplarily illustrated for the case of vegetable oils which served as sources of antioxidant-containing lipids. As a matter of fact, the difference in the effective radical-scavenging rate constants, determined for the antioxidative constituents of the sunflower and corn oils, perfectly matches the distinction of their qualitative tocopherol contents. In addition to the antiradical activity of lipid samples, the antioxidant potential of the latter may be modified by their influence on hydroperoxide stability, as it has been also demonstrated in the present work.

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In this review is given a detailed account of the mechanistic elucidation of the unique stereochemical double inversion observed in the nitrogen extrusion of bicyclic azoalkanes. It is shown that the judicious choice of experimental tools and theoretical approaches provides insight into and understanding of this perplexing stereoselectivity. This long‐standing mechanistic query serves as an example par excellence of harnessing the structural variation of the DBH‐type substrate (internal effects) and the change of medium properties (external effects) to diagnose a complex reaction mechanism. The particular case reviewed here is specific, but the focus in resolving its mechanistic complexities is general and, thus, may be applied to the elucidation of other intricate reaction mechanisms, primarily stereoselective and product‐selective organic transformations. Copyright © 2004 John Wiley & Sons, Ltd.