Download full text in PDF Opens in a new window. Article suggestions will be shown in a dialog on return to ScienceDirect. ... Please enable JavaScript to use all the features on this page. ... The first synthesis of natural (+)-catharanthine (ulbar>1) has been achieved in a few steps and in ∼20 % overall yield based on indole-3--acetic acid. The isomeric (±)-allocatharanthine was also prepared. ... Theodora W. Greene: Protective Groups in Organic Synthesis, Wiley- ...