(2S,4S)-2-(3-tert-Butoxycarbonylamino-propyl)-4-cyano-2-methoxymethyl-pyrrolidine-1-carboxylic acid tert-butyl ester

(2S,4R)-2-(3-Azido-propyl)-4-(tert-butyl-dimethyl-silanyloxy)-2-methoxymethyl-pyrrolidine-1-carboxylic acid tert-butyl ester

(2S,4R)-2-Allyl-4-(tert-butyl-dimethyl-silanyloxy)-2-methoxymethyl-pyrrolidine-1-carboxylic acid tert-butyl ester

(2S,4R)-2-(3-tert-Butoxycarbonylamino-propyl)-4-(tert-butyl-dimethyl-silanyloxy)-2-methoxymethyl-pyrrolidine-1-carboxylic acid tert-butyl ester

(2S,4R)-2-(3-tert-Butoxycarbonylamino-propyl)-2-methoxymethyl-4-(toluene-4-sulfonyloxy)-pyrrolidine-1-carboxylic acid tert-butyl ester