To a stirred solution of 4-hydroxy-benzaldehyde (0.24 g, 2mmol) and 1,16-dihydroxyhexadecane (0.51 g, 2 mmol), triphenylphosphine (0.53 g, 2 mmol) in dry THF (20 ml) at −15° C. under an argon atmosphere was added a solution of diisopropylazodicarboxylate (0.4 g, 2 mmol) in dry THF (7.5 ml) over a period of 40 minutes. The mixture was allowed to warm to room temperature overnight. The solvent was removed under reduced pressure, diethyl ether was added and the white solid formed was removed by filtration. The filtrate was evaporated to dryness and the residue purified by chromatography on a column of silica gel which was, eluted with petroleum ether (b.p. 40-60° C.):tetrahydrofuran (THF) (10:1 by volume) to yield the title compound which was used directly without further purification.
