Turning Information into KnowledgeScience of Synthesis: Houben-Weyl Methods of Molecular Transformations is the entirely new edition of the acclaimed reference series, Houben-Weyl, the standard synthetic chemistry resource since 1909. This new edition is published in English and will comprise of 48 volumes published between the years 2000 and 2008.Science of Synthesis is a quality reference work developed by a highly esteemed editorial board to provide a comprehensive and critical selection of reliable organic and organometallic synthetic methods. Science of Synthesis is designed to be the first point of reference when searching for a synthesis strategy.This volume is the third in Category 2 (Hetarenes and Related Ring Systems) of Science of Synthesis and deals with five-membered hetarenes with one chalcogen and one additional heteroatom. Throughout this category, a hetarene is considered to be a heterocyclic ring with a fully conjugated perimeter of pi- or nonbonding electrons. Additionally, potentially tautomeric systems with a hydroxy, sulfanyl, or amino substituent are included when conjugation is possible at least in one tautomer. In the Volume 11, this formal definition leads to quite different types of five-membered heterocyclic ring systems including the 1,2- or 1,3-arrangement of two chalcogen atoms to give cationic rings, as well as 1,2- or 1,3-combinations of a chalcogen atom and a nitrogen or phosphorus atom. The latter group comprises well-known ring systems such as oxazoles or thiazoles, but also less well-studied ring systems.For full information on the Science of Synthesis series, visit the Science of Synthesis Homepage. Series Editors: D. Bellus, S. V. Ley, R. Noyori, M. Regitz, E. Schaumann, I. Shinkai, E. J. Thomas, B. M. Trost, P. J. Reider