A New Protecting Group for Phenols: Phenylthiomethyl (PTM) Ethers

Abstract
Hemithioacetals have previously found utility as protecting groups for alcohols and phenols. In particular, the protection of alcohols2,3,4 and phenols5 as methylthiomethyl (MTM) ethers, and the facile hydrolysis of these ethers back to the parent alcohol or phenol have been reported. We now wish to report the use of phenylthiomethyl (PTM) ethers as phenolic protecting groups which may be differentiated from phenolic MTM ethers.