2616-81-1Relevant academic research and scientific papers
Diastereoselective episulfidation of strained cyclic alkenes by a thiophene endoperoxide versus epoxidation by dimethyldioxirane
Adam, Waldemar
, p. 8914 - 8919 (1998)
Thiophene endoperoxide 2, which was prepared by photooxygenation of thiophene 1, transfers a sulfur atom (up to 92%) to strained cycloalkenes to form thiiranes when thermolyzed in their presence. The diastereomeric pair cis/trans-cyclooctene (5b) reacted stereoselectively, which speaks for a concerted process rather than open dipolar and/or diradical intermediates. The set of chiral cyclooctenols 5c-e was also investigated, and the relative configurations of the respective thiiranes were assigned by chemical correlation and NMR spectral and X-ray analysis. The first-order kinetics of the process clearly shows that the endoperoxide 2 itself is not the sulfur- transferring species, but it is thermally transformed to the intermediates I and II. Whereas intermediate II is responsible for the competitive formation of elemental sulfur, intermediate I, presumably an oxathiirane, is the active sulfur-transferring species. The episulfidation was compared with the epoxidation by the related dimethyldioxirane, and both show the same qualitative trends in the diastereoslectivity and the reactivity toward the alkenes 5a-e.
Heterolytic Oxygen-Oxygen Bond Formation via gem-Dialkylperoxonium Ions
Best, Stephen P.,Bloodworth, A. J.,Spencer, Michael D.
, p. 416 - 418 (2007/10/02)
Different extents of decomposition for the cis and trans isomers of 4,5-epoxycyclo-octyl hydroperoxide coupled with the formation of oxygen (identified by Raman spectroscopy) and bicyclic ethers suggest a mechanism involving the heterolytic formation of protonated alkyl hydrotrioxides by nucleophilic attack of hydroperoxide on gem-dialkylperoxonium ions.
