Galanthamine N-oxide 2 undergoes a Polonovski-Potier reaction to give the iminium salt 5 and the unexpected 8-hydroxygalanthamine 3. An intramolecular oxygen transfer is proposed to explain hydroxylation of the aromatic nucleus.
to norgalanthamine 3 was selectively accomplished by a non classical Polonovskireaction using iron salts. This transformation constitutes the first example of the application of the Polonovskireaction to an N-oxide of a seven membered cyclic amine. Norgalanthamine is a valuable intermediate in new galanthamine derivatives synthesis.