REVIEWS The Art and Science of Total Synthesis at the Dawn of the Twenty-First Century** K. C. Nicolaou, Dionisios Vourloumis, Nicolas Winssinger, and Phil S. Baran Dedicated to Professor E. J. Corey for his outstanding contributions to organic synthesis At the dawn of the twenty-first cen-of the most exciting and important covery and invention of new synthetic tury, the state of the art and science of discoveries of the twentieth century in strategies and technologies; and explo- vnth