Organo Sulfonic Peracids. 4.(1) The Reaction of Arenesulfonylimidazoles with H(2)O(2) in the Presence of Ketones. A New Entry to Dioxiranes.

TLDR: The dioxirane oxidation pathway appears to be virtually exclusive one in this system in which only 5 equiv of ketone are used, and one example for the nonaqueous in situ generation of dimethyldoxirane is given.

Abstract: The reaction of ketones (acetone, 1,1,1-trifluoropropan-2-one) with the oxidation system (arenesulfonyl)imidazole (2)/H(2)O(2)/NaOH permits the in situ generation of the corresponding dimethyl- and methyl(trifluoromethyl)dioxirane in various solvents. This has been established by the chemoselective oxidation of azomethines 6, the diastereoselective oxidation of cholesterol (12), and (18)O-labeling experiments. Because only 5 equiv of ketone are used, the dioxirane oxidation pathway appears to be virtually exclusive one in this system. One example for the nonaqueous in situ generation of dimethyldioxirane (1a) is given.