To a cooled (−10° C.) solution of 8-(4-fluoro-3-methylphenyl)octanoic acid (0.486 g, 1.926 mmol) in 15 mL of THF, were added stepwise triethylamine (0.69 mL, 4.952 mmol) and pivaloyl chloride (0.23 mL, 1.889 mmol). The reaction mixture was stirred at −10° C. for 1 h and then LiCl (0.080 g, 1.889 mmol) and (R)-4-iso-propyloxazolidin-2-one (0.237 g, 1.834 mmol) were added stepwise. After being warmed slowly to room temperature and stirred for overnight, the reaction mixture was diluted with ethyl acetate (80 mL) and washed with saturated NaHCO3 solution and brine. The organic layer was dried (Na2SO4), filtered, and concentrated under reduced pressure. The product was isolated by Flash column chromatography (silica gel column) eluting with 0-100% dichloromethane/hexanes to give the title compound as colorless oil (0.547 g, 82% yield). GC-MS: tR=6.9 min; m/z 363 (M+).
