Total Synthesis of Silychristin, an Antihepatotoxic Flavonolignan

抄録

The total synthesis of silychristin, an antihepatotoxic flavonolignan, is described. The key intermediate, the transdihydrobenzofuran (15) was synthesized as follows. Treatment of the chalcone epoxide (9) with boron trifluoride etherate and subsequent reduction with sodium borohydride gave exclusively the erythro-1, 2-diaryl-1, 3-propanediol (10). Hydrogenolysis of 10 with hydrogen over a palladium catalyst followed by cyclization of the debenzylation product (13) with boron trifluoride etherate in acetic acid afforded 15 as a single product.