Styryl hydroperoxide

One such scheme involved the termination of the "living" particle with oxygen to give the lithium salt of styryl hydroperoxide. This salt was converted to the hydroperoxide by neutralization with acetic acid or to the peracetate by reaction with acetyl chloride. The yield of hydroperoxide was determined by titration of a slurry of the particles with iodine-thiosulfate. Figure 15 shows that at low temperatures essentially all of the carbanions are converted to hydroperoxide. 

For example, such a photooxygenation of alcohols 569 lead to unsaturated alcohol-hydroperoxides 570, which react with ketones and aldehydes to give 1,2,4-trioxanes 571 characterized by a-styryl-substituents at the 6-position (Scheme Geraniol... 

Using the normal addition procedure (02 diffusion into a 75/25 benzene/THF solution of poly(styryl)lithium) the 37% dimer fraction analyzed for 19% alkyl radical dimer and 18% macroperoxide after LiAlH4 reduction. The yield of macroperoxide was also confirmed by thermal decomposition experiments in refluxing toluene, followed again by size exclusion chromatography analysis of the dimer fraction. The amount of hydroperoxide could be deduced from the difference between the amounts of total peroxide (determined by iodometric titration) versus the amount of macroperoxide determined by LiAlH4 reduction. 

Mansson 319) has also investigated the products of the reaction of poly(styryl)-lithium with oxygen. Although products with carbonyl and alcohol functionality were detected, they may have resulted from the column and thin layer chromatographic work-up procedures employed. In conclusion, the oxidation of polymeric organo-lithium compounds is complex, but the possibility of manipulating the reaction conditions to form useful macroperoxides and hydroperoxides is real, as evidenced by the work of Brossas and coworkers 350). 

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