(R)-3-Phenyl-3-{[1-(2,4,6-trimethyl-phenyl)-meth-(E)-ylidene]-amino}-propionic acid tert-butyl ester

(R)-tert-butyl 3-(benzyl(((1R,2R,4R)-2-methoxy-7,7-dimethylbicyclo[2.2.1]heptan-1-yl)methyl)amino)-3-phenylpropanoate

(3R,αS)-tert-Butyl 3-(N-benzyl-N-α-methyl-4-methoxybenzylamino)-3-phenyl propanoate

tert-butyl (R)-3-[N-(tert-butoxycarbonyl)amino]-3-phenylpropanoate