Total synthesis of indole and dihydroindole alkaloids. XVI. Derivatives of vinblastine and vincristine: change of functionality in the vindoline unit

Studies describing the preparation of various derivatives of vinblastine and vincristine are presented. Vindoline (3) is transformed into a series of derivatives and the latter via Polonovski-type coupling with catharanthine (2) provide the bisindole alkaloid derivatives of the vinblastine series. Selective Jones' oxidation transforms the vinblastine family into the corresponding vincristine derivatives.