Thermolysis of thiete 1,1-dioxide and related species

Abstract

Thiete 1,1-dioxide (1) rearranges to 5H-1,2-oxathiole-2-oxide (3) on heating in solution or in the vapor phase. The presence of phenol in the solution leads to formation of phenyl 2-propene-1-sulfonate (CH2=CHCH2SO2OPh) in 15% yield. The results are rationalized in terms of a mechanism involving vinylsulfene (2). Flash thermolysis of some thietane 1,1-dioxides (16) and 3-thietanone 1,1-dioxides (15) gave products derived from extrusion processes, but 3-thietanol 1,1-dioxide (17) yielded, among other products, acetaldehyde and formaldehyde. The latter is believed to arise by "desulfinylation" of sulfene (CH2=SO2) formed along with the enol form of acetaldehyde by cycloreversion from 17.