| Flavonoids are a kind of important natural products, which distribut widely in citrus plants, are also one of the main active ingredients of medicinal plants . because of its unique chemical structure, Flavonoids play important role in physiological fact of mammals and other types of cells, such as antitumor, antiviral, antibacterial and antioxidant activity. Meanwhile, flavonoids contain so many active reaction spot that they show high reactivity in the reactions. This thesis mainly focused on the research working about the semi-synthesis of flavonols and flavonoids decorated glucose from naringin.1.The classification, characteristics, biological activities and the previous synthetic reports of flavonoids, are introduced briefly in this thesis. Meanwhile, the synthesis method of flavonoid glycosides and its application in pharmacology are also mentiond.2.A series of flavonoids compounds, such aschalcone, aurone, apigenin, kaempferol flavonoids and other natural medicinal ,are synthesized. First, starting from naringin, the aimd products are synthesized through acid hydrolysis, benzylation, and oxidation of DMDO. The thesis also discuss the synthesis method of flavonols, it shows that AFO reaction applys to the materials which 5-substituent has no substituent or smaller one, once the 5-substituent is large, it will force the carbonyl out-of-plane with the aromatic ring to get the aurone. For the formation of flavonls with 5-substituent, it is better to make acetone peroxide as oxidant to generate oxygen-containing three-membered ring to get the target products2, 9, 13.3.Based on diversity-oriented synthesis(DOS) strategy, it adopts Click chemistry ,which means 1, 3 - dipolar cycloaddition reaction from alkyne and azide compounds, to synthesis a series of 1, 2, 3 - triazole ring connected to the flavonoids glycoconjugates(17a-18a, 17b-18b, 19a) from flavonoids reliably, fast and efficiently.4.All of the synthesized compounds have been confirmed by 1H NMR, MS and IR. |
PDF Full Text Request