The hydroxyperoxides R2CH(OOR1)OH (R1 = CH3, C2H5; R2 = CH3, i-C3H7) and their isomeric alkoxyhydroperoxides R2CH(OOH)OR1 can be differentiated by their polarographic behavior. These hydroxyperoxides are not produced in the ozonolysis of trans 4-methyl-2-pentene in the presence of methanol or ethanol. It is concluded that the zwitterionic [Formula: see text] structure does not participate in the mechanism of ozonide formation.