Benzylation of morphinandienes and new aspects of their acid-catalyzed rearrangement to new aporphines

The benzylation of thebaine and 6-demethoxythebaine resulted in different product mixtures. Explanations were given for both the observed differences in the ratio of 5β- versus 7-benzyl products and the deviation of the electronic structure of ring C of 7-benzyl products. The acid-catalyzed rearrangement of morphinan-5,8-dienes, 5,6- and 6,7-disubstituted morphinan-6,8-dienes was achieved and mechanistic interpretations for the formation of new, potentially dopamine-active aporphines were provided.