A mixture of methyl (RS)-5-(3-iodophenyl)-4-(2-methylphenyl)-5-oxopentanoate (1.7 g), bis(triphenylphosphine)palladium (II) chloride (0.1 g), tetrakis(triphenylphosphine)palladium (0) (0.13 g) and benzylthiotrimethylstannane (1.17 g) in toluene (37 mL) is heated at reflux for 24 hours. The reaction mixture is washed twice with 10% aqueous potassium fluoride (20 mL), with water (20 mL), dried over magnesium sulphate and evaporated. The residue (2.87 g) is purified by flash chromatography on silica eluting with a mixture of pentane and ethyl acetate (98:2 v/v). Fractions homogeneous in the required product are combined and evaporated to give ethyl (RS)-5-(3-benzylthiophenyl)-4-(2-methylphenyl)-5-oxopentanoate as an orange oil (0.57 g).
