In this project, funded by the Chemical Catalysis Program of the Chemistry Division, Professor Cristina DeMeo of the Southern Illinois University Edwardsville is investigating structural modifications of sialic acid derivatives. Sialic acids are carbohydrates which are involved in numerous biological phenomena, ranging from cell-cell adhesion and mobility to oncogenesis and recognition by viruses and bacteria. The broader impacts include advancing the chemistry of sialic acids, enabling access to important biologically active sialic acids, and training undergraduate and Master's students, with an emphasis on recruiting and training underrepresented minorities. <br/><br/>Sialylations by chemical methods are often complicated by the intrinsic structural features of sialic acids, making the stereoselective synthesis of sialosides a challenge in carbohydrate chemistry. With the ultimate goal of gaining a better understanding of the roles of O-protecting groups in sialylations, this project is centered on the evaluation of sialyl donors functionalized at O-4 and O-7 positions. In addition, the research is addressing the influence of protecting groups at O-4 and N-5 on the conformation of sialic acids.