Protection for Phenols and Catechols

Ethers are the most widely used protective groups for phenols, and in general, they are more easily cleaved than the analogous ethers of simple alcohols. Esters are also important protective groups for phenols, but are not as stable to hydrolysis as the related alcohol derivatives. Catechols can be protected in the presence of phenols as cyclic acetals or ketals, or cyclic esters. Some of the more important phenol and catechol protective groups are included in Reactivity Chart 4 (Chapter 10).