SYNTHESIS OF VINCA ALKALOIDS AND RELATED-COMPOUNDS, PART LXXXIX - SOME UNEXPECTED REACTIONS OF COMPOUNDS CONTAINING THE D-SECO-ASPIDOSPERMANE RING-SYSTEM

Interaction of the tryptamine derivative (3) with the formyl ester (4) gave arbonyl)-3-phenyl-3,14-seco-20-epiaspidospermidine (7) instead o f the expected acetal (6). The product of the reaction of 3 with the a cetoacetic aldehyde derivative (5) was ethylene acetal of arbonyl-3-ph enyl-14,15-dinoraspidospermidin-19-one (8), it was readily convertible into the reactive intermediate (10). Further build-up starting from s econdary amine (11) gave the N(4)-substituted derivatives, while 10 af forded products with unexpected structures. The reaction of 10 with ac etic anhydride yielded different products depending on the reaction co nditions.