Lithium Chloride → (3S,4S)-4-t-Butoxycarbonylamino-3-hydroxy-6-methylheptanol

Participants

Reaction Steps

A solution of 1.0 g. (3.3 mmole) of ethyl (3S,4S)-4-t-butoxycarbonylamino-3-hydroxy-6-methylheptanoate prepared according to the method of D. Rich [J. Org. Chem., 43, 3624 (1978)] in 10 ml. of a 3:2 by volume mixture of ethanol and tetrahydrofuran was added to a suspension of 375 mg. (9.9 mmole) of sodium borohydride and 420 mg. (9.9 mmole) of lithium chloride in 30 ml. of a 3:2 by volume mixture of ethanol and tetrahydrofuran. The mixture was stirred overnight at room temperature, and then the excess reagents were decomposed with acetone. The solution was then concentrated by evaporation under reduced pressure, and water was added to the residue. The mixture was extracted with ethyl acetate, and the extract was dried over anhydrous sodium sulphate and then concentrated by evaporation under reduced pressure. The residue was purified by silica gel column chromatography (eluent: benzene/ethyl acetate). There were obtained 766 mg. of the desired product as an oil, [α]25 -38.2° (C=0.92, methanol).

Provenance & Evidence