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

(2S,1'''S,1''''R)-2-{2'-[[2''-(1''',2'''-bis(methoxycarbonyl)ethoxy)ethyl]-(1'''',2''''-bis(methoxycarbonyl)ethyl)amino]-ethoxy}-succinic acid dimethyl ester

N-(4-benzyloxycarbonylamidino-benzyl)-2-[(R)-3-oxo-4-(3-phenyl-propylamino)-morpholin-2-yl]-acetamide acid benzyl ester

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

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