Formation of alkyl and hydroxyalkyl hydroperoxides on ozonolysis in water and in air

Hydroperoxide-specific HPLC was used to determine the yields of alkyl and hydroxyalkyl hydroperoxides in the ozonolysis of ethene, propene, isoprene and α- and β-pinene under two sets of limiting conditions: in dry air and in aqueous solution. Ozonolysis in water (by mixing solutions) gives almost exclusively 1-hydroxyalkyl hydroperoxides, in 10–30% yields, while dry gas-phase ozonolysis gives very little peroxide (below 1%), unless the double bonds have methyl substituents, in which case methyl hydroperoxide is produced (up to 5%). Bubbling ozone through an aqueous solution of propene yields products typical of both the limiting cases.