Total Synthesis Of(+)-Decursivine And Studyieds On Some Polynitrogen Compounds

The total synthesis of (+)-decursive was completed in this dissertation.[3+2] reaction to construct a five-numbered all-nitrogen ring was investigated too. The dissertation can be mainly described as the following two parts:1. The retrosynthesis of decursive was designed on the basis of biosynthesis of serotobenine, which has the same skeleton with decursive. Two methods were chosen to construct the structure of2,3-dihydrobenzofuran. An oxidation-Michael addition process was investigated first, but failed to give the expected product. Then the bis(trifluoroacetoxy)iodobenzene-mediated intramolecular [3+2] cycloaddition reaction was investigated, and the expected product85a was achieved in66%isolated yield with excellent stereoselectivity.On the basis of the above [3+2] cycloaddition strategy, the natural (+)-decursive was achieved in11steps in11%overall yield starting from compound63b and piperonal.2. We tried to construct the five-numbered all nitrogen ring via the [3+2] reaction of diazo compounds and three-nitrogen dipolar molecules. The reactions of compounds99,95and DEAD with BnN3, PhN3were investigated, but all failed to give the pentazole derivatives.The Cu(I)-catalyzed [3+2] reactions of DEAD with BnN3, PhN3, TsN3were investigated, which afforded no cycloaddition products but some decomposed products.The reactions of a three-nitrogen dipolar molecule, compound115, with DEAD and PTAD were studied, but failed to give the desired products.