In 1.5 ml of dry dimethylformamide were dissolved 180 mg of octyl p-bromomethylbenzoate and 100 mg of (2S,5R)-2-hydroxy-5-hexyl-δ-valerolactone, and 300 mg of silver oxide was added to the solution and the mixture was stirred overnight at room temperature to effect reaction. After the reaction, diethyl ether was added to the reacted solution to extract the reaction product. The extract was washed with a saturated aqueous solution of sodium chloride and dried on anhydrous magnesium sulfate. Diethyl ether was removed by distillation under a reduced pressure. The obtained crude product was purified by the silica gel column chromatography to obtain 5 mg of (2S,5S)-2-(4'-octyloxycarbonylbenzyloxy)-5-hexyl-δ-valerolactone.
