The reaction of 3-hydroperoxy-4,4,5,5-tetramethyl-3phenyl-1,2-dioxolane, 1, with a series of sulfides (2a β«Χ‘β¬ thioanisole, 2b β«Χ‘β¬ ethyl phenyl sulfide, 2c β«Χ‘β¬ 2-chloroethyl phenyl sulfide, and 2d β«Χ‘β¬ 2-chloroethyl methyl sulfide) at 34ΠC in various solvents yielded the corresponding sulfoxides and 3-hydroxy-1,2-dioxolane 3 in quantitative yields. The oxidations showed excellent second-order kinetic behavior overall. In CDCl 3 , the reactivity order was 2d ΟΎ 2b ΟΎ 2a ΟΎ 2c. For 2a, the relative rate in various solvents was CDCl 3 (17); CD 3 OD (7); C 6 D 6 (Ο³3); CD 3 CN (1); CD 3 C(O)CD 3 (Ο³0.3). Addition of Ο³1 equivalent of acetic acid to reactions of 1 and 2a in CDCl 3 and C 6 D 6 resulted in small increases in the values of k 2 . The results are consistent with an electrophilic oxygen-atom transfer mechanism similar to that proposed for oxidations by β£-azohydroperoxides. Since the precursor to 1, 3-hydroxy-1,2-dioxolane 3, is regenerated during the oxidation, the system has the potential to be developed as a cyclic process.