Synthesis and NMR studies of chiral 4-oxazolidinones and rhodanines

Article abstract of DOI:10.1016/S0040-4020(01)88256-9

Sterically hindered N-(o-tolyl) and N-(o-chlorophenyl) substituted 2-thioxo-4-oxazolidinones 1 and-thiazolidinones (rhodanines) 2 forming enantiomers by partial rotation around the C - N bond are synthesized. Their chirality is proven by the presence of diastereotopic protons (or carbon atoms) detected by ¹H or ¹³C NMR (1c, 2c). In the presence of (S)(+)-1-(9-anthryl)-2,2,2-trifluoroethanol as an auxilliary the enantiomers showed ¹H shift differences of 0.01 ppm for otherwise isochronous nuclei.