(2R,3R)-tert-Butyl 2-azido-3-(N-benzyloxycarbonyl-N-methyl)aminobutanoate

(2S,3R)-tert-Butyl 2-tert-butyldimethylsilyloxy-3-(N-benzyloxycarbonyl-N-methyl)aminobutanoate

(2R,3S)-2-[4-(2-Ethyl-benzyloxy)-benzenesulfonylamino]-3-(2-hydroxy-ethylamino)-butyric acid tert-butyl ester

(2R,3S)-4-Acetyl-1-[4-(isoquinolin-4-ylmethoxy)-benzenesulfonyl]-3-methyl-piperazine-2-carboxylic acid tert-butyl ester

(2R,3R)-3-Methyl-1-[4-(2-trifluoromethyl-benzyloxy)-benzenesulfonyl]-aziridine-2-carboxylic acid tert-butyl ester