1: (tert-butoxycarbonyl)-L-proline pentafluorophenol ester With lithium diisopropyl amide in tetrahydrofuran T=-90°C; deprotonation; 0.333333 h; 2: acetone in tetrahydrofuran T=-90°C; cyclocondensation; 0.5 h; Further stages.;

1: 1-tert-butyl 2-phenyl pyrrolidine-1,2-dicarboxylate With n-butyllithium; diisopropylamine in tetrahydrofuran; hexane T=-78°C; deprotonation; 1.08333 h; 2: acetone in tetrahydrofuran; hexane T=-90 - 20°C; cyclocondensation; 4.83333 h; Further stages.;