(S)-1-Boc-4,4-dimethyl-pyrrolidine-2-carboxylic acid methyl ester

(S)-1-tert-butyl 2-Methyl 4,4-diMethylpyrrolidine-1,2-dicarboxylate

(S)-1-(tert-Butoxycarbonyl)-4,4-dimethylpyrrolidine-2-carboxylic acid