Precursor of O-substituted hydroxylamines, including the unstable O-acyl and O-sulfonylhydroxylamines which, having a good leaving group on nitrogen, are powerful aminating agents: J. Am. Chem. Soc., 82, 3133 (1960); Tetrahedron, 29, 1063 (1973); Synthesis, 140 (1972). For a review of O-mesitylenesulfonylhydroxylamine and related compounds, see: Synthesis, 1 (1977).