.1. Of Dmso Oxidation Of C <sub> 19 </ Sub> - Diterpenoid Alkaloids Generated Imine. Tetracyclines Structural Modification Of Exploration

Two projects were investigated in this paper.A new approach to the imine 2 by treating 14-OMs talatisamine (1) with DMSO was developed by our research group. A careful exploration of it's reaction conditions using talatisamine as starting material showed that imine 17 was prepared in a moderate yield (65%) by treating talatisamine (16) with DMSO at 100-130℃ for 3h. In order to observe the application of this method, we focused our attention on the different C₁₉-diterpenoid alkaloids. The installation of imines could be achieved in excellent yields (65-82%) by the substrates without the substituent groups at C-3 and C-6. In addition, the C₁₉-diterpenoid alkaloids having the substituent groups at C-3 and(or) C-6,afforded only the N-deethyl 化合物 s, instead of imine derivative.Some primary research to the chemical modification of tetracyclines were carried out . Several tetracycline derivatives were prepared.