I. Tabakovic et al., ANODIC C16-C21 FRAGMENTATION OF CATHARANTHINE IN METHANOL - SYNTHESISOF 16-METHOXYCLEAVAMINE, Perkin transactions. 2, (12), 1996, pp. 2741-2745
Two-electron controlled potential oxidation of catharanthine (Cath) af
fords 2 in 65% yield, Compound 2 is reduced to 16-methoxycleavamine in
95% yield, Cyclic voltammetry experiments show that catharanthine hyd
rochloride (CathH(+)) in methanol solution in the presence of 2,6-luti
dine exists in acid-base equilibrium with Cath as a free base which is
oxidized at 0.7 V vs, SCE, Oxidation of Cath to Cath(+) and fragmenta
tion of the C16-C21 bond is assumed to occur via a concerted mechanism
.