1-氨基-3-氧代环丁烷-1-羧酸乙酯

ethyl 1-<<(tert-butyloxy)carbonyl>amino>-3-(carbethoxymethylidene)cyclobutane-1-carboxylate

ethyl 1-[(tert-butyloxy)carbonylamino]-3-{2-[(tert-butoxy)carbonylamino]ethyl-thio}cyclobutane-1-carboxylate

cis-amino-3-(carbethoxymethyl)cyclobutane-1-carboxylic acid

1-amino-3-(3-phosphonopropyl)cyclobutane-1-carboxylic acid