A solution of diisopropylamine (344 μL, 2.45 mmol) in dry tetrahydrofuran (2.9 mL) was cooled to −78° C. under nitrogen and then treated with a 2.5M solution of n-butyllithium in hexanes (981 μL, 2.45 mmol). The reaction mixture was stirred at −78° C. for 15 min and then treated dropwise with a solution of (4-morpholin-4-yl-phenyl)-acetic acid methyl ester (549.9 mg, 2.34 mmol) in dry tetrahydrofuran (2 mL) and 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone (1 mL). The resulting reaction mixture was allowed to stir at −78° C. for 30 min, at which time, a solution of iodomethylcyclopentane (540.0 mg, 2.57 mmol) in a small amount of dry tetrahydrofuran was added dropwise. The reaction mixture was then allowed to warm to 25° C. where it was stirred for 67 h. The reaction mixture was quenched with water and then concentrated in vacuo to remove tetrahydrofuran. The aqueous residue was diluted with ethyl acetate (200 mL). The organic phase was washed with a saturated aqueous sodium chloride solution (1×100 mL), dried over sodium sulfate, filtered, and concentrated in vacuo. Flash chromatography (Merck Silica gel 60, 230-400 mesh, 3/1 hexanes/ethyl acetate) afforded 3-cyclopentyl-2-(4-morpholin-4-yl-phenyl)-propionic acid methyl ester (381.4 mg, 51%) as a white solid: mp 68-70° C.; EI-HRMS m/e calcd for C19H27NO3 (M+) 317.1991, found 317.2001.
