Eluciclation of the hydrophenanthrene structure of morphine, I4 and the related alkaloids, codeine and thebaine, has depended largely on their degradation to substituted phenanthrenes. The structures of most of these phenanthrenes have been established from analytical data and confirmed by synthesis following the general method of Pschorr. 5 However, evidence necessary to definitely assign the ethanamine chain to position CS- ...
