Ethyl chloroacetate → (5S)-5-cyclopropylmorpholin-3-one

To a cold, stirred suspension of sodium hydride (600 mg, 14.99 mmol) in toluene (20 mL) was added dropwise a solution of (S)-2-amino-2-cyclopropylethanol (680 mg, 6.72 mmol)) in toluene (12 mL). The reaction mixture was then allowed to warm to room temperature and a solution of ethyl chloroacetate (824 mg, 6.72 mmol) in toluene (4 mL) was added dropwise. The resulting mixture was stirred for 3 h at room temperature. The mixture was then quenched with the addition of 10 mL of 1N aq. hydrochloric acid and concentrated under vacuum. The residue was diluted with THF, dried with magnesium sulfate, concentrated under vacuum and filtered through a pad of silica gel, flushing with additional THF. The resulting filtrate was concentrated under vacuum, and the residue was further purified by flash chromatography (ISCO, 12 g silica gel column, using a 0-100% ethyl acetate in n-heptane gradient as the eluent to afford 208 mg of (S)-5-cyclopropylmorpholin-3-one as a white solid (MS: (M+H)+=142.2).