79328-88-4Relevant articles and documents
Synthesis and oxidative fragmentation of catharanthine analogs. Comparison to the fragmentation - Coupling of catharanthine and vindoline
Sundberg, Richard J.,Hong, Jian,Smith, Stanton Q.,Sabat, Michal,Tabakovic, Ibro
, p. 6259 - 6292 (2007/10/03)
Two new analogs of catharanthine have been synthesized in racemic form. They differ from catharanthine in the fusion of the indole ring to the non- aromatic portion of the iboga skeleton, with the [2,3] fusion present in catharanthine being replaced by [2,1] and [3,2] fusions. The corresponding deethyl analogs were also and methodological improvements were applied to an existing synthesis of deethylcatharanthine and a formal synthesis of racemic catharanthine. The reactivity of the catharanthine analogs toward coupling with vindoline was examined. Coupling was attempted by both the amine oxide fragmentation (Potier) and Fe3+ methods. Under Potier conditions the [2,1] fused analogs give low yields of coupling products in which vindaline is attached to the 3-position of the indole ring. The [3,2] isomers undergo fragmentation of the C16-C21 bond, as observed for catharanthine, but no coupling to vindoline occurs. The reactivity, oxidation potentials and conformation of the analogs are compared with catharanthine, deethylcatharanthine and N-methylcatharanthine.
Diels-Alder Adducts of 1-Benzenesulfonylindole-2-acrylates and 1-(Alkoxycarbonyl)-1,2-dihydropyridines. Intermediates for Synthesis of Iboga Alkaloid Analogues
Sundberg, Richard J.,Bloom, Jonathan D.
, p. 4836 - 4842 (2007/10/02)
Diels-Alder reactions between methyl 1-benzenesulfonylindole-2-acrylate and several 1-(alkoxycarbonyl)-1,2-dihydropyridines give protected methyl 7-(2-indolyl)-2-azabicyclooctene-7-carboxylates which serve as intermediates for the synthesis of analogues of the iboga alkaloids.Methods for deprotection of both the carbamate nitrogen and indole nitrogen are reported.The 7-(2-indolyl)-2-azabicyclooctene-7-carboxylates show a tendency to undergo fragmentation of the C-1,C-7 bond of the 2-azabicyclooctene ring, probably by retro-Mannich reactions.Several 6-nor-20-deethyl analogues of catharanthine have been prepared from intermediates derived from the deprotected Diels-Alder adducts.