An investigation of the water-soluble alkaloid fraction of the roots of T. dinklagei resulted in the isolation of the novel benzylisoquinoline alkaloid, oblongine (17). The identity of the isolated oblongine (17) was established by spectral means as well as by synthesis. During the course of the synthesis, several compounds (11, 12,13, 15,16,18, and 19) not previously reported were prepared. Their properties as well as those of certain related compounds are presented. © 1983, American Chemical Society. All rights reserved.