Antitumour alkaloids of the vinblastine-type: air oxidation of anhydrovinblastine
Abstract
A solution of anhydrovinblastine (3) in acetonitrile led, through a spontaneous oxidation–reduction process, not only to leurosine (4) and catharine (9) but also to other main antitumour alkaloids of Catharanthus spp.: vinblastine (5), leurosidine (6), and their deoxy derivatives (7) and (8).