| Abstract
| - Oxidation of trans-3,5-di-tert-butyl-3,5-diphenyl-1,2,4-trithiolane with dimethyldioxirane (DMD)or m-chloroperbenzoic acid (MCPBA) gave two stereoisomeric (1S*,3S*,5S*)- and (1R*,3S*,5S*)-1-oxides (16 and 17, respectively). Oxidation of 16 with DMD gave the (1S*,2R*,3S*,5S*)-1,2-dioxide(18) and the 1,1-dioxide 19, and that of 17 yielded the (1R*,2R*,3S*,5S*)-1,2-dioxide (20) mainlyalong with 18 and 19. The structures of the 1,2-dioxides 18 and 20 were determined by X-raycrystallography. 1,2-Dioxides 18 and 20 isomerized to each other in solution, and the equilibriumconstant K (20/18) is 19 in CDCl3 at 295 K. The kinetic study suggested a biradical mechanism forthe isomerization. Isomerization of 16 and 17 to cis-3,5-di-tert-butyl-1,2,4-trithiolane 1-oxides bytreatment with Me3O+BF4- is also described.
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