The (E)/(Z)-Ratio in the Reaction of 5-(2-Aryl-2-oxoethyl)-2-thioxo-4-oxo-1,3-thiazolidines with Bromine

Article abstract of DOI:10.1007/BF00813206

3-Aryl, 3-benzyl-, and 3H-5-(2-aryl-2-oxoethyl)-2-thioxo-4-oxo-1,3-thiazolidines 3a-h react with bromine in acetic acid solution to give mixtures of the respective 5-aroylmethylene (E) and (Z) diastereomeric derivatives 5 and 6.They contain more than 85percent of the (E)-diastereomers along with some pure isomers.The intermediacy of the 5-bromo derivatives 4 is proven and a plausible route of the reaction is presented.Structures of compounds 3-6 are evidenced by analytical and spectral data. - Keywords: (E)- and (Z)-3-Aryl-, 3-Benzyl-, and 3H-5-Aroylmethylene-2-thioxo-4-oxo-1,3-thiazolidines; (E)- and (Z)-5-Aroylmethylene-2,4-dioxo-1,3-thiazolidines; Bromine; Configurational assignment