(2S)-1-tert-butyloxycarbonyl-4-benzyloxycarbonyl-2-hydroxymethyl-5-pyrrolidone

N-(tert-butyloxycarbonyl)-γ,γ-dibenzyl-L-γ-carboxyglutamic acid α-tert-butyl ester

(2S)-1-tert-butyloxycarbonyl-4-benzyloxycarbonyl-5-oxoproline benzyl ester