: 1-tert-Butyl 2-Methyl (2S,4S)-4-Hydroxypyrrolidine-1,2-dicarboxylate, (2S,4S)-1-tert-Butyl 2-methyl 4-hydroxypyrrolidine-1,2-dicarboxylate, (2S,4S)-4-Hydroxypyrrolidine-1,2-dicarboxylic Acid 1-tert-Butyl 2-Methyl Ester, N-Boc-cis-4-hydroxy-L-proline Methyl Ester, Boc-cis-Hyp-OMe