(2S,4R)-4-tert-butoxy-2-(1,3-dioxo-1,3-dihydro-isoindol-2-ylmethyl)-pyrrolidine-1-carboxylic acid benzyl ester
(2S,4R)-4-tert-butoxy-2-(tert-butoxycarbonylamino-methyl)-pyrrolidine-1-carboxylic acid benzyl ester
(2S,4R)-2-aminomethyl-4-tert-butoxy-pyrrolidine-1-carboxylic acid benzyl ester