methyl 1-tert-butoxycarbonyl-4-oxo-3-ethyl-3-piperidinecarboxylate
3-(R,S)-benzyl-4-oxo-piperidine-1,3-dicarboxylic acid 1-tert-butyl ester 3-methyl ester
(R)-2-tert-butyl 8a-methyl 6-oxo-3,4,6,7,8, 8a-hexahydroisoquinoline-2,8a(1H)-dicarboxylate
(1-{1-(2,4-difluoro-benzyloxymethyl)-2-oxo-2-[3-oxo-3a-pyridin-2-ylmethyl-2-(2,2,2-trifluoro-ethyl)-2,3,3a,4,6,7-hexahydro-pyrazolo[4,3-c]pyridin-5-yl]-ethylcarbamoyl}-1-methyl-ethyl)-carbamic acid tert-butyl ester