Singlet reactions with unsaturated polymers

Singlet oxygen ( O2) reacts mainly with unsaturated polymers by "enetype" reactions with formation of hydroperoxy groups and shifting of the double bond ... 

In summary, this study has demonstrated that singlet oxygenation of cis- and trans-1,4-polybutadienes follows an ene -type reaction yielding allylic hydroperoxides in 1 1 correspondence with new shifted double bonds, and the latter are essentially all-trans. The ratio of relative rates for the 102 reaction with CB and TB (— 6 1) is approximately the same as that for cis- and trans-4-methyl-2-pentene. Evidently there are no fundamental differences in singlet oxygenation mechanism between the unsaturated polymers, CB and TB, and their low molecular weight counterparts. 

Singlet oxygen species 02( Ag) and 02( Sg) undergo versatile reactions with polymers containing ally lie and/or diene unsaturated bonds. Depending on... 

Scheme 7.8 Reactions of singlet nitrene with saturated and unsaturated polymers.

The reaction of singlet oxygen with double bonds is a convenient way to produce hydroperoxides both from unsaturated low molecular weight compounds as well as unsaturated polymers ". The reaction is quite selective (low formation of carbonyl and alcoholic by-products) with a yield up to 20 and 40 % according to the substrate. 

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