A uniform numbering system for indole alkaloids

M. Hesse,Indolalkaloide in Tabellen (Springer-Verlag, 1964).

R. Hegnauer, Planta med.6, 1 (1958).

R. Robinson,The Structural Relations of Natural Products (Clarendon Press, Oxford 1955).

E. Schlittler andW. I. Taylor, Exper.16, 244 (1960).

O. Bejar, R. Goutarel, M.-M. Janot, andA. LeHir, C. r. Acad. Sci., Paris244, 2066 (1957).

M. Przybylska andL. Marion, Canad. J. Chem.39, 2124 (1961).

K. Biemann, M. Spiteller-Friedmann, andG. Spiteller, J. Am. chem. Soc.85, 631 (1963).

There is another possible ambiguity, as illustrated by the cases of pleiocarpamine [M. Hesse, W. v. Philipsborn, D. Schumann, G. Spiteller, M. Spiteller-Friedmann, W. I. Taylor, H. Schmid, andP. Karrer, Helv. chim. Acta47, 878 (1964)], akuammicine [K. Aghoramurthy andR. Robinson, Tetrahedron1, 172 (1957)], and condylocarpine [K. Biemann, A. C. Burlingame, andD. Stauffacher, Tetrahedron Letters1962, 527]. Each of these Type I bases has a carboxyl group (present as a methylester) but subtraction of the tryptamine unit yields a 9 C rather than a 10 C residue. Although we assume this carboxyl group has the same derivation as the other Type I bases, it could conceivably have been derived from C-17.

R. H. F. Manske, Ed.,The Alkaloids, vol. 8 (Academic Press Inc., New York 1965).

E. Wenkert andN. V. Bringi, J. Am. chem. Soc.81, 1474 (1959).