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

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

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

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

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