Heterocycles play an important role in the design and discovery of new physiologically active compounds.[1] In the field of modern medicine “privileged structures,” groups of compounds whose members bind on different classes of receptors, have attracted much attention.[2] The best known examples are the benzodiazepines.[2] The xanthones, which have more than 600 members, over 100 of which display a tetrahydroxanthone moiety, ...
