title: Sulfur participation in [3,3]-sigmatropic rearrangements.
abstract: The thio-Claisen rearrangement is a general and facile process that is often advantageous overthe standard Claisen rearrangement. Several asymmetric variants of the thio-Claisen rearrangement havebeen reported. The rearrangement of sulfonium salts and sulfoxides takes place even more readily. Alkenylsulfoxides and sulfilimines undergo a highly stereocontrolled cyclization to lactones and lactams,respectively, upon reaction with haloketenes; this synthetically useful process entails a [3,3]-sigmatropicrearrangement of a zwitterionic intermediate. Sulfur-containing functionalities located at the peripheryof the Claisen substrates exert a powerful influence on the outcome of the process.
authors.affiliation: Instituto de Química Orgánica General, Consejo Superior de Investigaciones Científicas, c/ Juan de la Cierva 3, 28006, Madrid, Spain, iqofp19@iqog.csic.es.
authors.forename: Roberto Fernández
authors.initials: RF
authors.lastname: de la Pradilla
authors.forename: Mariola
authors.initials: M
authors.lastname: Tortosa
authors.forename: Alma
authors.initials: A
authors.lastname: Viso