Chemical topology topologically complex molecules, formation

Up to this point, we have emphasized the stereochemical properties of molecules as objects, without concern for processes which affect the molecular shape. The term dynamic stereochemistry applies to die topology of processes which effect a structural change. The cases that are most important in organic chemistry are chemical reactions, conformational changes, and noncovalent complex formation. In order to understand the stereochemical aspects of a dynamic process, it is essential not only that the stereochemical relationship between starting and product states be established, but also that the spatial features of proposed intermediates and transition states must account for the observed stereochemical transformations. 

Both molecules, 28 and 30, are topologically chiral the chirality of 30 was proven by H-NMR spectroscopy with the addition of KPFs and Pirkles reagent. This resulted in different chemical shifts for the hydrogen atoms of the clover-leaf knot 30 due to formation of diastereomeric complexes. 

---