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

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

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

(R)-2-{2-[((S)-1-tert-butoxycarbonyl-1-phenylmethyl)amino]ethoxy}-succinic acid dimethyl ester

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