Synthesis Of Antidiabetic Flavonoids And Their Derivatives

Flavonoids are a class of natural organic compounds widely existing in plants. They are the active ingredients in many Chinese herbal medicines. It is reported that they have a broad spectrum of biological activities. Many natural flavonoids play an important role in the prevention of diabetes and its complications. On the basis of previous research, we designed and synthesized the following flavones and their derivatives.First, we used 2,4,6-trihydroxyacetophenone as our starting material and selectively protecting 5-and 7-hydroxy groups. Then, we got a series of chalcones by Aldol condensation. Chalcones were further cyclized with a catalytic amount of sodium acetate to give the corresponding flavanones. Finally, products were obtained by cleavage of the MOM group under acidic conditions.We used two different synthetic routes to synthesis two new flavones, 5,7,4′- trihydroxy-3′-methoxyflavone and 5,7,4′-trihydroxy-3′-chloroflavone. The second one has not been reported.There is no literature reporting in detail the preparation of flavonols bearing 5-and 7-hydroxy groups. Until now, only have flavonols without 5-and 7-hydroxy groups been synthesized via the classical Algar-Flynn-Oyamada method. Using this method, we have successfully synthesized four flavonols which do not have 5-and 7-hydroxy groups. Then, we tried to use this method to synthesize flavonols bearing 5-and 7-hydroxy groups, but in vain. We only got two important aurones- 2,6-dihydroxy-3′,4′-dichloroaurone and 2,6-dihydroxy-4′-methyl aurone, and the first of which has not been reported.