Patented Routes for the Preparation of the Morphinan Derivatives Hydromorphone and Hydrocodone Via Catalytic Isomerization

Hydromorphone and hydrocodone are widely used narcotic analgesics. In this mini-review article, processes for the preparation of these semi-synthetic opioids from the naturally occurring opiates morphine and codeine, respectively, via catalytic isomerization of the allylic alcohol unit of the latter are discussed. Relevant patents in the field are presented.