Stereoselective synthesis of enantiopure gamma-aminoalcohols by reduction of chiral beta-enaminoketones

The results of the reduction of chiral beta-enamino ketones with sodium borohydride in acetic acid are reported. The reaction is convenient, stereoselective and high yielding and allows the preparation of enantiopure gamma-amino alcohols in syn diastereoselectivity. The reaction is easy to perform and does not require expensive or hazardous chemicals. A mechanistic hypothesis is presented. The absolute configuration of the products obtained is attributed by correlating 1H NMR spectral data with conformational analysis performed by molecular modelling, and confirmed by X-ray analysis.