4-Piperidineacetic acid,1-[2-[3,4-dimethoxy-2-(phenylmethoxy)phenyl]-2-hydroxyethyl]-5-ethyl-2-oxo-, ethyl ester, [1(S*),4a,5b]-(±)-

4-Piperidineacetic acid,1-[2-[3,4-dimethoxy-2-(phenylmethoxy)phenyl]-2-hydroxyethyl]-3-ethyl-2-oxo-, ethyl ester, [1(R*),3a,4b]-(±)-

(4S,5R)-(-)-1-(2-(2-Hydroxy-3,4-dimethoxyphenyl)-ethyl)-5-ethyl-2-oxo-4-piperidineacetic Acid Ethyl Ester