New oxidative transformations of phenolic and indolic oxazolines: An avenue to useful azaspirocyclic building blocks

The oxidative cyclization of a phenolic amide to a spirolactam has long bee n regarded as an "impossible" reaction, because exposure of the substrates to a variety of oxidants results in formation of spirolactones with consequ ent loss of the amine segment. We recently communicated that this heretofor e unknown transformation may be achieved by oxidation of oxazoline analogue s of phenolic and indolic amides. Herein, we provide full details of our wo rk.