for the following products
(2S)-4,4-Difluoro-1-[(2-methylpropan-2-yl)oxycarbonyl]pyrrolidine-2-carboxylic acid | (2S)-4,4-Difluoro1,2-pyrrolidinedicarboxylic acid 1-(1,1-dimethylethyl) ester | Boc-L-Pro(4,4-F2)-OH | N-tert-Boc-4,4-Difluoro-L-proline and N-Boc-4,4-Difluoro-L-proline
