The focus of this research is the utilization of allene oxides and cyclopropanones as synthetic intermediates for the synthesis of a wide range of carbocyclic and heterocyclic ring systems occurring in natural products. The thermal rearrangement of fulvene endoperoxides gives rise to the desired intermediates. Intramolecular McMurray reactions, claisen condensations, enol lactone formation and sigmatropic shifts are among the reactions to be explored. The investigations will be carried out with the help of undergraduate coworkers. With this Research in Undergraduate Institutions award, the Organic and Macromolecular Chemistry Program is supporting the research and educational activities of Dr. Ihsan Erdan of the Department of Chemistry and Biochemistry at San Francisco State University. Professor Erdan, with the help of undergraduate participants, will focus his work on using the synthetic intermediates obtained from the thermal rearrangement of cyclic peroxides, fulvene endoperoxides, for the synthesis of a wide range of natural products.