The first synthesis of 3 (S), 17-dihydroxytanshinone was achieved by ultrasound promoted Diels–Alder reaction of the protected 3-hydroxymethyl-4, 5-benzofurandione with a vinylcyclohexene derivative. Bioassay showed that the synthetic 3 (S), 17- dihydroxytanshinone was active in vitro against HL-60 tumor cell line by MTT method.