(4R,5R)-5-ethyl-1-<2-(1H-indol-3-yl)-2-oxoethyl>-2-oxo-4-piperidineacetic acid ethyl ester

(3R,4R)-(+)-6-ethoxy-3-ethyl-2,3,4,5-tetrahydro-4-pyridineacetic acid ethyl ester

5-ethyl-1-[2-(1H-indol-3-yl)ethyl]-5,6-dihydro-1H-pyridin-2-one