(2S,5S)-5-methyl-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-ethyl ester

二碳酸二叔丁酯

cis-5-methylproline

(S)-5-methyl-3,4-dihydro-2H-pyrrole-2-carboxylic acid ethyl ester

(S)-2-tert-butoxycarbonylamino-5-oxo-hexanoic acid ethyl ester