Chemical examination of Tylophora asthmatica-III : the complete structure of tylophorine

2,3,6,7-Tetramethoxyphenanthrene-9,10-dicarboxylimide has been synthesized and proved to be identical with the oxidation product of tylophorine isomethohydroxide, confirming the previous formulation of tylophorine as 2,3,6,7-tetramethoxyphenanthro (9,10,6',7')-indolizidine. Some further interesting degradation reactions on tylophorine have been carried out