Apical Ligand Preference and Fluxional Behavior of Some Sulfuranes

Article abstract of DOI:10.1021/jo00335a029

Sulfides 4, 11, and 12 react with m-chloroperbenzoic acid to form apically unsymmetrically substituted sulfuranes 18-20, respectively, instead of the isomeric symmetrically substituted dialkoxysulfuranes.Rapid equilibration (ΔG*_{12 deg C} = 14.7 kcal mol^-1) of isomers of sulfurane 18 is observed and studied by (1)H NMR spectroscopy.An associative mechanism for these interconversion processes is proposed.Potassium salts of 18 and 19 are symmetrical dialkoxysulfuranes 21 and 22, respectively.Other reactions involving these sulfuranes are also reported.