synthesis are discussed. Substitution of the bromo nucleofug in the 2-position of 1,3-dicarbonylcompounds as well as of a 3-oxosulfone by selected sulfur nucleophiles is assumed to follow an SRN1 pathway. Characteristic properties, some typical reactions, and selected derivatives were studied. S-Alkyl- and S-aryl-substituted cyclic 2-thioreductones have been found to be synthons for the preparation of vinylogous