N-[1-(S)-乙氧羰基-3-苯丙基]-L-丙氨酸

N-Cbz-4-keto-L-proline ethyl ester

N-[(phenylmethoxy)carbonyl]-1,4-dithia-7-azaspiro[4.4]nonane-8(S)-carboxylic acid ethyl ester

N-cbz-4-氧-L-脯氨酸

5,5-dimethyl-2-methylsulfanyl-4,5-dihydro-oxazole-4-carboxylic acid ethyl ester