This volume presents work from six different groups working on various aspects of cycloaddition chemistry. José Mascareñas gives us a very interesting account of the chemistry of & Bgr;-alkoxy- & ggr;-pyrones and related species. Al Padwa and Chris Staub discuss further advances in rhodium carbenoid chemistry and the unusual cycloaddition processes possible with these intermediates. Higher order cycloadditions mediated by transition metals highlight Jim Rigby's update on his group's efforts in this area. Lily Lee and John Snyder present us with a detailed account of the indole ring as a dienophil.