2-Chlorotrityl chloride resin (2.55 g of nominal loading 1.3 mmol/g) was swelled with dichloromethane (20 mL). After draining, a solution of 4-(4-iodo-phenoxymethyl)-5-methyl-furan-2-carboxylic acid (26) (1.18 g) and diisopropylethylamine (2.3 mL) in dichloromethane (30 mL) was added and the mixture was shaken at room temperature for 72 hours. The resin was drained, washed sequentially with dichloromethane/triethylamine/methanol (20:1:3 by volume) (3×30 mL), dichloromethane (6×30 mL), N,N-dimethylformamide (2×25 mL), dichloromethane (6×25 mL), and diethyl ether (2×25 mL) and dried at 40° C. in vacuo, (ii) A stirred mixture of the resin from (i) (0.38 g), 4-chlorophenylboronic acid (0.30 g), [1,1′-bis-(diphenylphosphino)-ferrocene]-dichloropalladium(II) complex with dichloromethane (1:1) (30 mg), potassium acetate (0.20 g) in N,N-dimethylformamide (15 mL) was heated at 40° C. for 48 hours. The resin was drained, then washed sequentially with tetrahydrofuran/water (1:1 by volume), tetrahydrofuran, N,N-dimethylformamide, dichloromethane, diethyl ether and then dried at 45° C. in vacuo. The resin was treated with dichloromethane/trifluoroacetic acid (19:1 by volume) (20 mL) for 20 mins and the solution drained from the resin. This procedure was repeated. The combined solutions were concentrated in vacuo and the residue purified by HPLC to afford compound 27 as a white solid (43 mg). LC/MS System D: Rt=8.83 mins, m/z (ES−)=341 (M− for C19H15ClO4).
