Photochemical one-pot synthesis of vinblastine and vincristine.

The naturally occurring cytostatic dimer alkaloids vinblastine 1 and vincristine 2 were photochemically synthesized in slightly acidic aqueous solution from the monomer alkaloids catharanthine 3 and vindoline 4. Multi-centre reactions should obviously be involved and some of the principal photochemistry-associated phenomena here discussed are quite likely to be characteristic even to the biosynthetic reactions yielding vinblastine 1 and vincristine 2 in the cells of Catharanthus roseus.