leading to the total synthesis of 18,19-dehydrotabersonine, described in the following paper, some older work on the synthesis of (±)-3-oxo-20-desethyl-20-allylvincadifformine, its C-20 epimer, and (±)-3-oxo-19-vinylvincadifformine is reported. Attempts to convert these compounds,by appropriate manipulation of the isolated double bond, into a wide range of anilinoacrylate alkaloids, minovincine, tuboxenine