Editorial [Hot Topic:Synthetic Organic Chemistry (Guest Editor: Antonino Corsaro)]

With this second part of the special issue on “Synthetic Organic Chemistry”, inserted in the Volume 11, Number 12, August 2007 of Current Organic Chemistry, I close, as Guest Editor, the first year of activity, including three reviews which deal with the chemistry of sulfenic acids, and furan oxidations, and photooxygenation of non-aromatic heterocycles. The first review, written by M.C. Aversa, A. Barattucci, P. Bonaccorsi and P. Giannetto of the Department of Organic and Biological Chemistry in Messina University, includes 56 references and provides a comprehensive survey of the literature on sulfenic acid chemistry from 1990 through June 2006, focusing the attention on salient aspects of their structures and involvement in organic processes. The stability of some sulfenic acids has allowed the comprehension of their chemical and physical properties and indirectly of the role that Cys-SOHs play in protein biochemistry. However, in many papers of organic chemistry their intermediacy is apparent: once generated, they are involved in intra- and intermolecular additions to unsaturated molecules. Few examples of sulfenic acid addition to double and triple bonds have been recently described and most of them are intramolecular processes. Some applications there are also described where the thermical elimination from sulfinyl precursors is used as a method for removing the sulfinyl moiety from organic molecules and forming double bonds with controlled stereochemistry, in addition to the way to generate sulfenic acids. The second review, provided by M. R. Iesce, F. Cermola, and M.Rubino of the Department of Organic Chemistry and Biochemeistry of Naples University, Federico II, was dedicated to the photo-oxygenation of non-aromatic heterocycles. The review, including 102 references, furthermore, deals with cyclic compounds containing non usual hetero-atoms, namely silicon, germanium and tellurium, and involves all the three types of photo-oxygenation (Types I-III). Moreover, the hetero-atom can be frequently involved endorsing electron-transfer reactions which turn out to be the main pathways, even in singlet oxygen oxygenation. There is a vast collection of photo-oxygenation examples, where novel and unexpected products are formed, some times in a stereochemical manner. P. Merino, T. Tejero, J. I. Delso and R. Matute of the Laboratorio de Sintesis Asimetica in the Departamento de Quimica Organica, Universidad de Zaragoza, and Departamento de Ingenieria Quimica y Tecnologias del Medio Ambiente of the Escuela Universitaria de Ingenieria Industrial in Zaragoza, Aragon (Spain) have contributed to the third work where of oxidation reactions of several furan derivatives as effective methods for the preparation of key synthetic intermediates are reviewed. Recent advances and applications of furan oxidations in organic synthesis are described, where, depending on the oxidizing reagent, the furan ring can be considered as a C-1 or C-4 synthon, leading, upon different conditions, to 1,4- dicarbonyl compounds, carboxylic acids, pyranones or butenolides. I would like to my sincere thanks are expressed to the contributors of this second part of this special issue on “Synthetic Organic Chemistry” for their excellent reviews on their very interesting researches.