Lithium borohydride → Tert-butyl (3-benzyloxymethyl-1-hydroxymethyl-4-methylpentyl)carbamate

Participants

Reaction Steps

A solution of 20.0 g of methyl 4-benzyloxymethyl-2-tert-butoxycarbonylamino-5-methylhexanoate [180182-92-7] in 320 ml of tetrahydrofuran at room temperature is admixed with 2.64 g of lithium borohydride in portions. After 4 hours, the reaction mixture is quenched with 200 ml of methanol dropwise over 1 hour and subsequently concentrated cautiously by evaporation. The residue is admixed once again with 150 ml of methanol and again concentrated by evaporation to dryness. The residue is admixed with 100 g of ice and 400 ml of 1N HCl and extracted with dichloromethane (3×)—the combined organic phases are washed with water, dried over sodium sulphate and concentrated by evaporation. The title compound is obtained as an beige oil from the residue by means of flash chromatography (SiO2 60F). Rf=0.32 (1:1 EtOAc-heptane). Rt=4.96 (gradient I).

Provenance & Evidence