HIGHLY CHEMOSELECTIVE REDUCTION OF N-BOC PROTECTED LACTAMS

N-Boc protected lactams can be reduced chemoselectively in the presenc e of other groups such as esters, nitriles, carbamates or double bonds by first reducing the amide carbonyl group into the corresponding hem iaminal using lithium triethylborohydride followed by further reductio n of the hemiaminal intermediate with triethylsilane/Boron trifluoride etherate. This method preserves the chirality present in the substrat e.