To a 15 mL of anhydrous DMF was added NaH (60% dispersion in oil, 338 mg, 8.44 mmol), and the resulting reaction mixture was cooled to 0° C. p-benzyloxy phenol (1.41 g, 7.03 mmol) was added and the reaction mixture was stirred at rt for 45 min. It was then cooled to −5° C., and (R)-Boc-prolinol tosylate (2.5 g, 7.03 mmol) in anhydrous DMF (5 mL) was cooled in a separate ice-bath and added dropwise to the reaction mixture. It was then allowed to warm to rt and stirred at 92° C. for 5 h and at rt overnight. The resulting mixture was poured into 200 mL ice/water and stirred for an hour. The resulting precipitate was filtered, washed with ether, dried over MgSO4, concentrated, recrystallized with ether/hexane to give shiny yellow crystals (1.5 g, 55%).
