(R)-[3-(tert-butyl-dimethyl-silanyloxymethyl)-2-oxo-5-phenyl-2,3-dihydro-benzo[e][1,4]diazepin-1-yl]-acetic acid ethyl ester

N-(fluorenylmethyloxycarbonyl)-L-aspart-α-al β-tert-butyl ester