ethyl 2-(3-oxocyclohexyl)acetate
Ethyl α-(1-methyl-2-pyrrolidinylidene)acetate
(4S)-4-<(tert-butyloxycarbonyl)amino>-5-<1-<(4-methylphenylsulphonyl)>imidazol-4-yl>-3-oxopentanoic acid ethyl ester
(2S,3R)-3-Ethoxycarbonylmethyl-2-(1H-indol-3-yl)-5-oxo-piperidine-1-carboxylic acid benzyl ester
(R)-8-Benzyloxycarbonylamino-4-tert-butoxycarbonylamino-3-oxo-octanoic acid ethyl ester