Rigid, polycyclic cage systems of high symmetry and strain are of special interest, both for the fundamental aspects of their chemistry and as sources of new and unusual kinds of materials not found in nature. Cubane, an example nonpareil, is now available sufficiently easily and in sufficient quantity to use the system as a practical starting material for the synthesis of other exceptional ring systems, e.g. azahomocubanone, dehydrocubane, azacubane, 1,1':3,3'-biscyclobutane, etc. These systems are important as probes into the effects of well-defined, but unusual molecular structure on bonding, reactivity, and other properties which will be evaluated in the course of this work. As such compounds and their derivatives are completely new ring systems of very novel type they present opportunities for the discovery of new pharmacologically valuable materials. Further, as the geometric requirements of the carbon framework of these systems are far from ordinary, tactical synthesis is an exceptional challenge. The work therefore will also result in the development of new ways for building and manipulating the skeletons of complex systems. The whole project will push outward the frontiers of organic structural and synthesis research.