Synthesis Of Amorfrutin B,the Natural Product From The Extracts Of The Fruits Of Amorpha Fruticosa

Amorfrutin B, an active substance from Amorpha fruticosa, displays interesting biological activities including antioxidant, antimicrobial, antiinflammatory, antifungal,antitumor and potent activity of lowering blood glucose. In this thesis, taken Pd(0)-catalyzed one-pot cascade reaction as key step, Amorfrutin B was synthesized efficiently, starting from Meldrum’s acid and geraniol within six steps. The overall yield was 8.7 %.In this thesis, we synthesized Amorfrutin B and five key intermediates, which are intermediate 3((E)-3-(3,7-dimethylocta-2,6-dienyloxy)-3-oxopropanoic acid), intermed iate 6((E)-3,7-dimethylocta-2,6-dienyl-4-(2,2-dimethyl-6-oxo-6H-1,3-dioxin-4-yl)-3-oxobutanoate), intermediate 9((E)-3,7-dimethylocta-2,6-dienyl-2-(2-(2,2-dimethyl-6-oxo-6H-1,3-dioxin-4-yl)acetyl)-3-oxo-5-phenylpentanoate), intermediate 10((E)-7-hydroxy-2,2-dimethyl-8-(3,7-dimethylocta-2,6-dienyl)-5-phenethyl-4H-benzo [d][1,3]dioxin-4-one) and intermediate 11(E)-7-methoxy-2,2-dimethyl-8-(3,7- dimeth ylocta-2,6-dienyl)-5-phenethyl-4H-benzo[d][1,3]dioxin-4-one. The experimental conditions were optimized, and the production cost was reduced. We also explained the mechanism of palladium(0)-catalyzed tandem decarboxylation-geranyl migration- aromatization reaction. The structures of all intermediates and final compound were characterized by FTIR, 1H NMR, 13 C NMR and MS.The synthesis of Amorfrutin B has not been reported. In this thesis, the total synthesis of Amorfrutin B, a bibenzyl natural product has been achieved. In conclusion,the advantages associated with our method such as simplicity, good availability for starting-material and easy operation made this process suitable for batch production in high overall yield.