Oxidation of the tumor inhibitory alkaloid thalicarpine (1), a benzylisoquinoline-aporphine dimer, with VOF3 in TFA gave a mixture of diastereoisomeric dienones 2 and 3, a new type of proaporphine-aporphine alkaloid. The major isomer 2 was converted to the epimeric dienols 6a and 6b which, upon treatment with BF3-Et2O in CH2CI2, gave another new type of alkaloid, bisaporphine 8. Preliminary testing results indicate that bisaporphine 8 is active in vitro against cells derived from the human carcinoma of the nasopharynx (KB). © 1978, American Chemical Society. All rights reserved.