Hydroxylation by hydrogen peroxide and inorganic catalysts

Direct addition of hydrogen peroxide to double bonds of olefins in accord with the reaction  

Treibs135,136 those metal oxides are suitable that are readily converted by hydrogen peroxide into inorganic peracids. Detailed studies of the catalysts named above have been instituted by Mugdan and Young.137 

Hydroxylation of olefins by hydrogen peroxide in the presence of osmium tetroxide leads to cis-glycols because a cyclic osmic ester is formed as intermediate and the cis-glycol is formed by hydrolysis of that intermediate. Other catalysts afford fraws-hydroxylation, which occurs by way of an intermediate epoxide.138 

Oxidation of olefins by hydrogen peroxide and catalytic amounts of osmium tetroxide is effected in anhydrous tert-butyl alcohol (Milas reagent139), ether,122 aqueous methanol,140 or acetone.141 Also, tert-butyl hydroxyperoxide may be used in place of hydrogen peroxide.142 

Hydroxylation of polyolefins by Milas reagent can be so arranged that only one double bond is affected e.g., cyclopentadiene gives a mixture of 3-cyclo-pentene-l,2-diol and 4-cyclopentene-l,3-diol.139,143 Another application of this method was the selective oxidation of / -carotene to vitamin-A aldehyde.144 

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