I Declared Weiwu Head Alkaloids Ii. Paclitaxel Analogues Synthesis Research Ix. Norepinephrine Diterpenoid Alkaloids From The Conversion Of The Synthesis Of Paclitaxel Analogues

In this dissertation the following two sections are included. 1. Investigation on the phytochemistry of the plant Aconitum nagarum var. lasiandrum. Fourteen diterpenoid alkaloids have been isolated from the crude n-2-butanol extracts of the root of this plant, three of which were new C₁₉-diterpenoid alkaloids. They are francheline (1), lasianine (2), and lasiansine (3). The remained known alkaloids are 16-epi-pyroaconine (4), neoline (5), talatisamine (6), isotalatizidine (7), chasmanine (8), 15α-hydroxyneoline (9), 1-epi-aconine (10) , songoramine (11), 12-epi-19-dehydronapelline (12), songorine (13) and 12-epi-napelline (14). The structures of new alkaloids were elucidated on the basis of spectral methods (¹H NMR, ¹³C NMR, 2D-NMR, HR-MS, and IR).Lasianine is the third naturally-occuring aconitine-type diterpenoid alkaloid with an 8-NH2. In addition, 16-epi-pyroaconine(4) and 1-epi-aconine(10) were isolated from the plant for the first time.2. Studies on the conversion of the norditerpenoid alkaloids into taxoids. On the basis of our previous work on the conversion of the norditerpenoid alkaloids into taxoids, this dissertation described the further research on the modification of ring A in 7,17-seco compounds. In the conversion strategy II, we studied the key reactions related to ring B, including the enlargement of ring B and functionalization at C₇ and C₈. In studies on the key reactions related to ring C, we investigated the functionalization at C₁₂ and Baeyer-Villiger oxidation of 14-keto compounds. In addition, we investigated deoxymethylation and the reaction of norditerpenoid alkaloids with HNO2.In researches of the modification of ring A, with starting from talatisamine, we have designed three routes: the cleavage of N-C₁₉, N-C₁₇, and C₄-C₁₉ bonds.