1. Am. med. Ass. approved generic names are vinblastine (VLB), vincristine (VCR), vinrosidine (VRD), and vinleurosine (VLR), respectively. VCR is supplied as oncovin (vincristine sulfate, Lilly) and VLB as VELBAN (vinblastine sulfate, Lilly).
2. N. Neuss, L. L. Huckstep andN. J. Cone, Tetrahedron Lett.91, 811 (1967).
3. N. Neuss, J. Am. chem. Soc.86, 1440 (1964).
4. P. Bommer, W. McMurray andK. Biemann, J. Am. chem. Soc.86, 1439 (1964).
5. Acknowledgments. We wish to thank Mr.J. L. Occolowitz for the high resolution mass spectral data, Mr.T. K. Elzey for the1H-NMR spectra, Mr.G. M. Maciak for microanalyses and Mr.R. J. Armstrong for the isolation of the partially purified alkaloid.