摘要:
The reaction of ketones (acetone, 1,1,1-trifluoropropan-2-one) with the oxidation system (arene-sulfonyl)imidazole (2)/H2O2/NaOH permits the in sitzi 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 a of cholesterol (12), and O-18-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.