@article{DzambaskiMarkovicKleinpeteretal.2013, author = {Dzambaski, Zdravko and Markovic, Rade and Kleinpeter, Erich and Baranac-Stojanovic, Marija}, title = {2-Alkylidene-4-oxothiazolidine S-oxides - synthesis and stereochemistry}, series = {Tetrahedron}, volume = {69}, journal = {Tetrahedron}, number = {31}, publisher = {Elsevier}, address = {Oxford}, issn = {0040-4020}, doi = {10.1016/j.tet.2013.05.087}, pages = {6436 -- 6447}, year = {2013}, abstract = {A series of 5-unsubstituted and 5-substituted 2-alkylidene-4-oxothiazolidine-S-oxides were synthesized by the sulfur-oxidation with m-CPBA. The stereochemistry of 5-substituted sulfoxides was determined by means of NMR spectroscopy and DFT theoretical calculations. It was found that the thermodynamically less stable anti-isomer was initially formed in the course of the oxidation, but it underwent epimerization to the mixture enriched in the more stable syn-isomer, during the work-up process. The higher stability of syn-isomers is ascribed to the stronger hyperconjugative sigma(C-H)->sigma*(S-O) interaction versus the weaker sigma(C-C)->sigma*(S-O) delocalization in their anti-counterparts and to the existence of intramolecular 1,5-CH center dot center dot center dot C hydrogen bonds.}, language = {en} }