1,2-Piperidinedicarboxylic acid, 5,5-difluoro-, 1-(1,1-dimethylethyl) ester
1-(1,1-Dimethylethyl) 5,5-difluoro-1,2-piperidinedicarboxylate
1-(tert-Butoxycarbonyl)-5,5-difluoropiperidine-2-carboxylic acid
1-[(tert-Butoxy)carbonyl]-5,5-difluoropiperidine-2-carboxylic acid