A new method for the deprotection of benzyl ethers or the selective protection of alcohols

A new selective method for the deprotection of benzyl ethers situated next to alcohols in the alpha, beta, or gamma position is presented which uses either NIS or DIB/I2 as a reagent. After initial formation of a hypoiodite intermediate, the reaction is believed to follow a radical pathway to resemble the Hoffman-Loffler-Freytag reaction. The formation of the intermediate hypoiodite is suggested on the basis of NMR studies. Depending on the substrate, the corresponding benzylidene derivatives or diols are isolated.