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 covers the synthesis of five-membered heterocyclic compounds with either two nitrogen or phosphorus atoms or five-membered heterocycles containing both one nitrogen and one phosphorus atom. The oxidation state of the described heterocycles corresponds to the maximum unsaturation. Maximum unsaturation means that the cyclic conjugation in the five-membered ring must not be interrupted by either an sp3-hybridized carbon atom or a heteroatom incapable of pi-conjugation.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