Diisobutylaluminum hydride → 2,2-Bis(tert-butoxycarbonylamino)-5-oxo-pentanoic acid benzyl ester

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Reaction Steps

A solution of DIBAL (1.0 M, 14.7 mL, 14.7 mmol) in hexane was added dropwise to a solution of 2,2-bis(tert-butoxycarbonylamino)-4-(methoxy-methyl-carbamoyl)-butyric acid benzyl ester (4 g, 10.5 mmol) under an atmosphere of nitrogen at −78° C. After 2 hours the mixture was quenched with saturated ammonium chloride (30 mL) and allowed to warm to room temperature. Water (20 mL) was added, and the mixture was extracted with diethyl ether (3×50 mL). The combined organic phases were left to stand at room temperature for 15 minutes. The resulting thick gel was filtered through a pad of CELITE. The filtrate was dried over sodium sulfate, filtered and the solvent was removed under reduced pressure to provide 2,2-bis(tert-butoxycarbonylamino)-5-oxo-pentanoic acid benzyl ester (3.34 g, 7.9 mmol, 75%). This was used immediately in the next step.

Provenance & Evidence