The development of a palladium-mediated cyclization via isomerization using a vinyl epoxide as an initiator and an amine as a terminator led to a facile cyclization to produce isoquinuclidines. The synthesis of the requisite cyclization precursor from (-)-quinic acid led to obtention of the isoquinuclidines in optically pure form. The substitution pattern of the resultant isoquinuclidine would allow further cyclization to either enantiomeric series of the iboga alkaloids. This “pseudo-meso” intermediate then can become a common intermediate to either ibogamine or catharanthine, the latter of particular importance in the synthesis of vinblastine analogues. During this study it has been observed that the olefination of an epoxy ketone proceeds with high geometrical control.
|Number of pages||11|
|Journal||Journal of Organic Chemistry|
|State||Published - 1986|