Syntheses of Cyclic Peroxides with Oxygen

Autoxidation140 of suitable olefins, particularly 1,3-dienes, leads to cyclic peroxides (though mostly in low yields) as well as polymeric peroxides. These autoxidations occur when the olefins are aerated with oxygen, and does not usually require exposure to light or the use of sensitizers. Only a few papers have been published in this field, and these are mostly due to Hock et al.147-183 

Following the autoxidation of cyclohexa-1,3-diene and cyclopenta-diene at 15 to 20°, Hock and Depke147 isolated small yields of the cyclic peroxides 147 and 148, respectively. 147 can be obtained in better yields by photosensitized oxidation of cyclohexa-1,3-diene (see Section IV, B) and by the action of hydrogen peroxide and sodium hypochlorite on cyclohexa-1,3-diene154. In the last reaction, oxygen 

Vinyl-substituted aromatic compounds such as a-methylstyrene,148 /S-isopropylstyrene,148 1-phenylcyclohexene,153 indene, 149 and 1,2-dihydronaphthalene151,152 give cyclic peroxides on autoxidation. For example, /3-isopropylstyrene gives the 1,2-dioxene derivative (149) together with polymeric peroxide. After the er -alkyl hydroperoxide formed by attack of oxygen on the isopropyl group had been reduced with sodium sulfite, 149 could be isolated in 26.4% yield by means of an alumina column. 

The autoxidation of bicyclohexenyl leads to a mixture of cyclic peroxide (150), hydroperoxide, and polymeric peroxide.153 

Cyclic peroxides are also formed in the autoxidation of polyolefinic acids157 and squalene.168,169 

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