This volume of Progress in Heterocyclic Chemistry(PHC) is the thirteenth annual review of the literature, covering the work published on important heterocyclic ring systems during 2000. In this volume there are two specialized reviews. The first, by H. Ila, H. Junjappa and P.K. Mohanta, covers their work on annulation using ?-oxoketene dithioacetals, a synthetic method that provides useful routes to an impressively wide range of fused heterocycles. The second, by R. N. Warrener, is on the synthesis of fused 7-azanorbornanes. The 7-azanorbornane structural unit is incorporated into a series of elegant polycyclic molecules with rigid geometry. The subsequent chapters, arranged by increasing heterocycle ring size, review recent advances in the field of heterocyclic chemistry with emphasis on synthesis and reactions.