Benzyl alcohol bond cleavage, homolytic

Kita and coworkers use potassium bromide to depolymerize iodosobenzene 17 by generating an I—Br bond. Homolytic cleavage of the I—Br bond to generate the iodine-centered radical allows formation of the benzylic radical 18. The authors propose the benzylic radical is trapped by bromine radical to generate a benzylic bromide 19, a known byproduct of the reaction conditions. Conversion to the alcohol and subsequent oxidation yields the aryl ketone 20. While the ketone products are useful themselves, Ochiai utilizes this mechanism, though with a different hyperva-lent iodine reagent, to deprotect benzylic ethers such as 21 to alcohols 2. ... 

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