1 Introduction By JOHN A. JOULEaAND JOHN P. RICHARDb aDepartment of Chemistry The University of Manchester Manchester UK M13 9PL bDepartment of Chemistry State University of New York at Buffalo Buffalo NY 14260–3000 USA Annual Reports B aims to provide an overview of the most important advances and achievements in Organic Chemistry and related fields described in the literature of a calendar year. It is not comprehensive and is not intended to be comprehensive. The reviewers comment and emphasise the significance and usefulness–of new synthetic methods of newNMRtechniques of new chromatographic methods etc.–so that the non-specialist can use the volume as an easy access to recent significant developments. It aims to be a short-cut to useful recent material. It is the only publication which provides this global year-by-year coverage.It is di¶cult to define subjects for chapters to prevent overlap–perhaps this is not a fault for topics can be usefully discussed from more than one viewpoint. This year sees material subdivided in a somewhat di§erent way to that employed in previous volumes in this series. The Scientific Editors would welcome comments on this new format and suggestions for its improvement. Reviews of Biosynthesis (dealt with this year) will be biennial covering a two-year period and will alternate with two-year reviews of Natural Products. The interests of organic synthesis will we hope be better served by new subdivisions chapters on Pericyclic Methods Heteroatom Methods Free-radical Reactions Enzyme Chemistry and Protecting Groups will focus attention.Organometallic chemistry formerly covered as a single non-focused chapter has been subdivided into discussions of Stoichiometric Methods and Palladium and Nickel Catalysed Methods. Discussions of Aromatic Chemistry and of Heterocyclic Chemistry follow the pattern of previous Volumes. The chemistry of organic polymers will be covered on a biennial basis–Synthesis of Man-made Polymers (dealt with this year) alternating with Natural Polymers. Finally a chapter on Synthesis Highlights–the year’s tours de force–will concentrate on the strategic aspects of such achievements. This volume features several chapters on topics which have been neglected in recent years. The chapter on Free-radical Reactions provides coverage of thermochemical and theoretical studies on neutral free-radical and radical ions.The characterization of novel pathways for the generation of these species is reported and studies of the mechanisms for their rearrangement elimination and addition reactions are summarized. The chapter on Bioorganic Chemistry presents an overview of recent advances in our understanding of the chemical mechanism for enzyme catalysis of simple 1 organic reactions and on the role and mechanism of action of coenzymes in these reactions. The chapter on NMR Spectroscopy describes recent advances in the application of NMR to monitoring the progress of organic reactions to the determination of the chemical structure and conformation of complex organic molecules and to the development of structure–activity relationships for drug discovery. In addition advances in NMR methodology of specific interest to the organic chemist are reviewed. Many of these chapters provide evidence for the increasing reliance placed on modern computational methods in rationalizing the results of studies on organic reaction mechanisms. The chapter on Theoretical Organic Chemistry provides an indepth description of recent advances in computational chemistry which allow for calculation of the structure and energy of stable organic molecules and of unstable reaction intermediates and transition states with an ever-increasing degree of accuracy. 2 John A. Joule and John P. Richard