Synthesis, crystal structure and anti-malarial activity of functionalized spiro-1,2,4,5-tetraoxacycloalkanes from unsaturated hydroperoxy peracetals

Treatment of unsaturated hydroperoxy peracetals with bis(sym-collidine)iodine(I) hexafluorophosphate affords a series of iodine-containing spiro-1,2,4,5-tetraoxacycloalkane derivatives in high yield. In addition, ozonolysis of unsaturated hydroperoxy peracetals in AcOH–CH2Cl2 also results in the formation of spiro-1,2,4,5-tetraoxacycloalkanes. Two of the new compounds, 3-methyl-3-methyldioxy-1,2,6,7-tetraoxaspiro[7.11]nonadecane and dimethyl-4-iodo-1,2,6,7-tetraoxaspiro[7.11]nonadecane, exhibit significant in vitro antimalarial activity against P. falciparum with EC50 values of ca. 10−7 M.