Synthesis of orthogonally protected (3R, 4S)- and (3S, 4S)-4,5-diamino-3-hydroxypentanoic acids

The paper describes two methods of the synthesis of ethyl (3R, 4S)- and (3S, 4S)-4-[(benzyloxycarbonyl)amino]-5-[( tert-butyloxycarbonyl)amino]-3-hydroxypentanoates, useful for the syntheses of edeine analogs. Differently N-protected (S)-2,3-diaminopropanoic acid was used as a substrate in both procedures. The absolute configuration of newly generated asymmetric carbon atoms C-3 in beta-hydroxy-gamma, delta-diamino products was assigned by means of (1)H NMR spectroscopy after their transformation into corresponding piperidin-2-ones.