合成路线1

Reaction of 9a-hydroxyandrost-4-ene-3,17-dione (I) with benzenesulfinyl chloride and pyridine gives the corresponding sulfinate (II), which by treatment with TsOH in refluxing chloroform yields androsta-4,9(11)-diene-3,17-dione (III). Reaction of the androstadienedione (III) with acetylene by means of potassium tert-butoxide in THF affords the 17a-ethynyl derivative (IV), which is treated with phenylsulfenyl chloride and TEA at ­70 C to provide the sulfenate ester (V). Rearrange-ment of sulfenate (V) by warming at ­40 C gives the allene sulfoxide (VI), which is treated with sodium methoxide in methanol at 25 C to yield the enol ether sulfoxide (VII). Then, by refluxing in methanol, an equilibrium between sulfoxide (VII) and sulfenate (VIII) occurs. Reaction of the non-isolated sulfenate (VIII) with the thiophile trimethyl phosphite affords the 17a-hydroxy enol ether (IX), which is finally converted to anecortave acetate by either treatment with peracetic acid and NaHCO3 in dichloromethane or bromination with Br2 and pyridine in dichloromethane to give compound (X) followed by treatment with KOAc, KI and AcOH in refluxing acetone.