(1-Nosyl-5-nitroindol-3-yl)methyl Ester: A Novel Protective Group for Carboxylic Acids

Abstract

The usefulness of (1-nosyl-5-nitroindol-3-yl)methyl esters as a novel protective group for carboxylic acid is fully demonstrated. The novel protective group is stable under a broad range of conditions and can easily be deprotected under the mild conditions used for removal of the nosyl (Ns) group. It is orthogonal to the existing protective groups for carboxylic acids such as t-butyl and allyl esters.