Addition of oxygen to ethylenic bonds

Molecular oxygen can add to the double bonds of olefins such as styrene, 1,1-diphenylethylene, dimethyl- and diethyl-ketene, vinyl acetate, cyclopentadiene and cyclohexadiene with formation of polymeric peroxy compounds. The course of the reaction corresponds to that of a mixed polymerization 1 r 2 3 4b d 

Most of the mixed polymerisates with oxygen are extremely explosive special protective measures are required when working with them, and these are collected in the Section on Formation of peroxides by autoxidation.  

According to Staudinger5 1,1-diphenylethylene peroxide is obtained as follows 10 g of 1,1-diphenylethylene are placed in a small vessel fitted with an interior cooler and are irradiated by a 500-candle-power metal-filament lamp while oxygen is passed through. After 3 days, addition of light petroleum precipitates 0.5-1 g of colorless, amorphous diphenylethylene peroxide. After being washed with ether it decomposes at 131-132°C. 

In contrast to this formation of polymeric peroxides from olefins and oxygen, photosensitized autoxidation of dienes leads to cyclic monomeric 

Epidioxides (sometimes called endoperoxides) can be prepared from acenes, from suitable steroids, and from dienes of low molecular weight ( e.gcyclo-hexadiene).13 Irradiation is essential for initiation of reaction, and sensitizers must sometimes be added. 

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