Triphenylphosphine → (R)-4-Bromo-2-[[(tert-butoxy)carbonyl]amino]butanoic acid tert-butyl ester

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Reaction Steps

A mixture of 1.39 g (5.05 mmol) tert-butyl N-(tert-butoxycarbonyl)-D-homoserinate (prepared according to J. Org. Chem. 1988, 53, 1900-1903), 899 mg N-bromo succinimide (5.05 mmol), and 1.68 g polymer bound triphenylphosphine (loading approx. 3 mmol/g, approx. 5.0 mmol) in dichloromethane (17 mL) was stirred overnight at room temperature. All solids were removed by filtration, and the filtrate was concentrated in vacuo. The residue was purified by column chromatography on silica gel (2.5→25% ethyl acetate in hexane) to give 580 mg of the title compound (34% yield).

Provenance & Evidence