Ir and pmr spectra of 2‐aryl‐4‐thiazolidinones. III. Stereochemical analysis of 2‐aryl‐3‐(2‐pyridyl)‐4‐thiazolidinones

The long‐range coupling through the sulphur atom observed in a number of 2‐aryl‐3‐(2‐pyridyl)‐4‐thiazolidinones suggests that the C 2 proton and one of methylene protons are in a cis 1,3 diequatorial relationship. Some additional information concerning the preferred orientations of the substituents in this system are given from Eu(fod) 3 , [tris(1,1,1,2,2,3,3‐heptafluoro‐7,7‐dimethyloctane‐4,6‐dionato)]europium, induced shift data.