Chemistry of amine–boranes. Part 5. Reduction of oximes, O-acyloximes, and O-alkyl-oximes with pyridine–borane in acid

Oximes, O-acyl-oximes, and O-alkyl-oximes were reduced with pyridine–borane in the presence of acid to the corresponding hydroxylamine derivatives without over-reduction. Unstable O-acyl-hydroxylamines were directly synthesized for the first time from the corresponding O-acyl-oximes.