The flavonolignan (±)-silybin (1), having an antihepatotoxic activity, has been synthesized via a key intermediate (9), which was prepared from readily available starting materials (2) and (3). The aldehyde (9) was transformed to the methoxymethyl ether (10), which was condensed with an acetophenone derivative (11) to yield the chalcone (12). Oxidation of the chalcone (12) with alkaline hydrogen peroxide, followed by treatment of the resulting epoxide (13) with hydrochloric acid afforded (±)-1.