The development and application of cycloaddition methodology continues to be at the forefront of research in synthetic organic chemistry. This volume begins with a review of methods available for the synthesis of seven-membered rings and is followed with work on metal-catalyzed cycloadditions. There is then an update on the cycloaddition chemistry of 2-pyrone, and then a unique application of photocycloaddition is detailed. The final chapter is a discussion of the latest explorations of the reaction of rhodium-stabilized vinyl carbenoids with dienes.