Abstract
Treatment of some C19-diterpenoid alkaloids (3, 6, 10 and 12) with anhydrous DMSO at 100–170°C for 3–7 h led to the formation of the corresponding imines (4, 7/8, 11, 13/14) in 65–83% yield, respectively. This is a new simpler formation of the imines of the C19-diterpenoid alkaloids.
Acknowledgements
Financial support for this research was provided by the National Natural Science Foundation of China (No. 30472075). We also thank Professor Xiao-Tian Liang, Institute of Materia Medica, Chinese Academy of Sciences, Beijing, for helpful discussion on the manuscript.