Diisopropylethylamine → (4S)-3-((2R)-3-cyclopentyl-2-{[(phenylmethyl)oxy]methyl}propanoyl)-4-(phenylmethyl)-1,3-oxazolidin-2-one

Participants

Reaction Conditions

Reaction Steps

To a solution of (4S)-benzyl-3-(3-cyclopentylpropanoyl)oxazolidin-2-one (42.4 g, 141 mmol) in dichloromethane (500 mL) at 0° C. under nitrogen was added titanium (IV) chloride (1 M in DCM, 155 mL, 155 mmol) in a slow steady stream. After 5 min, diisopropylethylamine (27 mL, 155 mmol) was added dropwise. After stirring at 0° C. for 1 h, benzyloxymethylchloride (TCI-America) (39 mL, 280 mmol) was added in a slow steady stream to the resulting titanium enolate, and the mixture was maintained at 0° C. for 3.5 h. The reaction mixture was then quenched with water (400 mL). The aqueous layer was extracted with dichloromethane (150 mL×2). The organic extracts were washed with saturated NaHCO3, were dried (MgSO4) and were evaporated. The residue was washed with ether (2×), and then was triturated with hexanes/ether to provide 2 crops of (4S)-3-((2R)-3-cyclopentyl-2-{[(phenylmethyl)oxy]methyl}propanoyl)-4-(phenylmethyl)-1,3-oxazolidin-2-one as a pale yellow solid (42.7 g, 72%). LCMS: (M+H)+: 422.2.

Provenance & Evidence