Naloxol
Naloxol is an opioid antagonist closely related to naloxone. It exists in two isomeric forms, α-naloxol and β-naloxol.
α-naloxol is a human metabolite of naloxone. Synthetically, α-naloxol can be prepared from naloxone by reduction of the ketone group, and β-naloxol can be prepared from α-naloxol by a Mitsunobu reaction.
Naloxol can be said to be the oxymorphol analogue of naloxone.