Methylene-indolines, indolenines et indoleniniums—XII : Hemisynthese de la dehydro-14,15 vincamine et de la criocerine

Resume (-)-Tabersonine 1 was oxidised and rearranged to (+)-14,15-dehydrovincamine 5, (+)-14,15-dehydro,16-epi vincamine 6 , and the rhazinilam derivative 9 . Iodine and potassium iodate oxidised 5 to 14 -iodo criocerine 13 , Which led to criocerine 14 .