A solution of 4-hydroxymethyl-5-methyl-furan-2-carboxylic acid methyl ester (16) (1 g) in anhydrous tetrahydrofuran (20 mL) was cooled to 0° C. under a nitrogen atmosphere. 4-Hydroxybiphenyl (3 g) and triphenylphosphine (4.61 g) were added and the mixture was treated with diisopropylazodicarboxylate (3.46 mL) dropwise. The mixture was stirred at 0° C. for 10 min then cooling was removed and the mixture stirred for a further 3 hours. The solvent was removed in vacuo and the residue was partitioned between ethyl acetate (50 mL) and water (100 mL). The organic phase was separated, dried and evaporated. The residue was purified by flash chromatography, eluting with pentane/ethyl acetate 9:1 by volume to give a mixture of the title compound and 4-hydroxybiphenyl (1.8 g). This material was purified further by flash chromatography eluting with dichloromethane/methanol 99:1 by volume to give compound 17 as a white solid (200 mg). LCMS System A: Rt=4.2 mins.
