Sodium Methoxide → (2S,3R)-3-(4-Benzyloxy-2-methyl-phenyl)-2-ethoxy-3-hydroxy-propionic acid methyl ester

A 5.4 M solution of sodium methoxide (7.3 ml, 39.5 mmol) was added to an ice-cooled and stirred suspension of (S)-4-benzyl-3-[(2S,3R)-3-(4-benzyloxy-2-methyl-phenyl)-2-ethoxy-3-hydroxy-propionyl]-oxazolidin-2-one (17.6 g, 36 mmol) in dry methanol (87 ml). The mixture was stirred at 0° C. for 15 min, quenched and neutralized by the addition of dilute aqueous hydrochloric acid (1.0 M). The solution was concentrated under reduced pressure and the residue dissolved in ice water/ethyl acetate 1/1. The layers were separated and the aqueous layer was extracted two times with ethyl acetate. The combined organic layers were washed with ice water and dried over sodium sulfate. The solvent was removed under reduced pressure and the residue purified by column chromatography (silica gel, cyclohexane/AcOEt) to give 8.6 g (25 mmol, 69%) of the title compound as light yellow oil. According to 1H-NMR spectroscopy, one single diastereomer was obtained.