Chapter 1 reviews the literature with regard to the synthesiS of substituted carbazoles via the cycloaddition reactions of indole-2,3-quinodimethanes and its equivalents with dienophiles. Particular attention is paid to the synthesis and reactions of pyrano[3A-b ]indol-3-ones. Chapter 2 describes the synthesis of a variety of linked indole-3-acetic acid derivatives, where the linkage is either through the indole nitrogen, the 2- position or the acetic acid residue in the 3-position. The preparation and subsequent Diels-Alder reactions of the derived linked pyrano[3,4-b]indol-3-ones are also described. Chapter 3 investigates the possibility of forming a benzothiophene containing polymer via a novel double Diels-Alder reaction. The preparation of thieno[2,3- c]pyran-3-ones and their transformation into benzothiophenes are described. Chapter 4 briefly discusses the relevance of molecular recognition to a variety of fields and introduces the idea of folded and stretched conformations in non-rigid systems. The work described concentrates on the solid state structures obtained for a variety of simple linked heterocycles.