A regio- and stereoselective didehydrodimerization procedure, whose key step involves the anodic oxidation, allows the conversion of beta-anilinoacrylic alkaloids belonging to the Aspidosperma class, typified by tabersonine (1) and its 3-oxo derivative 2, into the hitherto unknown 16,10'-didehydro dimers 3 and 7, respectively.