{1-Benzyl-2-[(E)-cyanoimino]-5-oxo-imidazolidin-4-yl}-acetic acid methyl ester
(S)-1-Benzyl-2-[(E)-cyanoimino]-6-oxo-hexahydro-pyrimidine-4-carboxylic acid tert-butyl ester
(R)-1-Benzyl-2-[(E)-cyanoimino]-6-oxo-hexahydro-pyrimidine-4-carboxylic acid tert-butyl ester
N-(9-phenylfluoren-9-yl)-L-aspartic acid α-t-butyl β-methyl diester
1-(tert-butyl) 4-methyl N-benzyl-N-(9-phenyl-9H-fluoren-9-yl)-L-aspartate