[(R)-4-benzenesulfonylamino-3-oxo-morpholin-2-yl]-acetic acid

(R)-2-{2-[(1,1-dicyclohexylmethyl)amino]ethoxy}-succinic acid dimethyl ester

[(R)-3-oxo-4-phenylmethanesulfonylamino-morpholin-2-yl]-acetic acid methyl ester

[(R)-3-oxo-4-phenethylamino-morpholin-2-yl]-acetic acid

[(R)-3-oxo-4-phenethylamino-morpholin-2-yl]-acetic acid methyl ester