This thesis describes the development of some synthetic methodology applicable to the preparation of the spirobicyclic ring system of the marine natural product oscillatoxin D (1, Figure 1.1). Our goal was to find an efficient way to synthesize a major intermediate for the model compound (2) and thus to provide a guide for the subsequent synthesis of the natural product. Oscillatoxin D has shown some antileukemic activity and it might have undiscovered biological activity. It is a possible drug candidate.