Organic stereochemistry. Part 6 : the conformation factor in molecular pharmacology

Following the previous Part on the mechanisms of chiral recognition in pharmacology, the road was open to cover one aspect of stereoselectivity that had been evoked in Part 5 but not discussed explicitly, namely the pharmacological significance of the conformational behavior of active molecules. There, we saw how ligands and binding sites adapt to each other, but these results were not related explicitly to the conformational behavior of the ligand. The focus of the present Part is to use a few well-known drugs, examine their conformational behavior, compare the 3D geometry of probable conformers with rigid analogs acting at the same receptor, and reflect on the concept of 'active conformation'.