A New Approach to Morphinans: Total Synthesis of O-Methylpallidinine

Article abstract of DOI:10.1021/jo00194a026

We have devised a general method for the synthesis of 4a-aryloctahydroisoquinolines related to morphine and have shown how these compounds may be used in a route to morphinan alkaloids.The key step in this route involves the addition of diazomethane to a 4a-aryloctahydroisoquinolinium salt, followed by spontaneous cyclization to the morphinan.Studies of this step indicate that it is not compatible with the presence of an alkoxyl group at C4 of the aryl ring.The value of this method has been demonstrated in the context of stereospecific total synthesis of O-methylpallidinine.