The mercury(II)-promoted hydrolysis of the 2-phenyl-1,3-oxathiolane and 2-T-butyl-2-phenyl-1,3-oxathiolane.

摘要

his was a kinetic study of the hydrolysis of two cyclic O,S-acetals promoted by heavy metal ions. Results of the study of the hydrolysis of 2-phenyl-1,3-oxathiolane and 2-t-butyl-2-phenyl-1,3-oxathiolane established that (1) the rate-determining step can be either acid-catalyzed hydrolysis of mercury(II) complex promoted hydrolysis depending on the concentration ratio of mercury(II) chloride to acid; (2) increasing the steric bulk near the reaction center decreases the rate of reaction; (3) the state of complexation of the mercury(II) is critical to its reactivity. This reactivity can be directly correlated to the electrophilicity of the mercury(II) ion. Experiments were performed defining the rate-limiting step under a variety of conditions. The second-order rate constants measured for the acid catalyzed hydrolysis for 2-phenyl-1,3-oxathiolane and 2-t-butyl-2-phenyl-1,3-oxathiolane were