Diethyl Malonate → (5R)-5-[(1S)-1-[[(1,1-Dimethylethoxy)carbonyl]amino]-2-phenylethyl]tetrahydro-2-oxo-3-furancarboxylic Acid Ethyl Ester

Participants

Reaction Conditions

Reaction Steps

A solution of tert-Butyl(1S)-1-[(2S)-oxiran-2-yl]-2-phenylethylcarbamate (10.0 g, 38.0 mmol) and diethyl malonate (9.0 ml, 59.3 mmol) in ethanol (27 mL) at 0° C. was treated with a solution of NaOEt (16 mL, 21% in ethanol) over 10 minutes, stirred at 70° C. for 2 hours, cooled to 0° C. and quenched with 10% citric acid solution, and partitioned between ethyl acetate and water. The organic phase was washed with saturated NaHCO3and brine, dried over MgSO4, filtered and concentrated. The residue was chromatographed on silica gel eluting with 0-35% ethyl acetate in hexanes to give the title compound (13.3 g, 93% yield).

Provenance & Evidence