Synthesis of novel conjugates of tetraoxane endoperoxide with bis(quaternary ammonium salts)

Novel water-soluble conjugates of 1,2,4,5-tetraoxane bis(quaternary ammonium salts) were synthesized in a relatively stable crystalline form via four steps starting from methyltrioxorhenium-catalyzed endo-peroxidation of ethyl 4-oxocyclohexanecarboxylate with hydrogen peroxide in hexafluoro-2-propanol. The assay for the in vitro toxicity of water-soluble tetraoxanes 5a–5d to malaria parasites indicate that they were inactive against the Plasmodium falciparum FCR-3 strain.