(+)-Codeine and (+)-Morphine from Sinomenine

The former trials to obtain ( + )-codeine (I) from ( + )-1, 5, 7-tribromodihydrothebainone (II) were fruitless, on account of the instability of the latter against caustic alkali. It gave always 1-bromosinomeninone (III) by the treatment with this reagent. The action of pyridine on (II) or (IV) was the formation of an yellow pyridinium bromide, which was very resistant to cleavage. Mattox-Kendall's methodJ~ to use 2, 4-dinitrophenylhydrazine seemed to be the only promising method for our purpose and we made actually some preliminary experiments in this direction.