| —— | 
                                        (4S,5S)-1-(2-benzyloxy-3,4-dimethoxyphenethyl)-5-ethyl-2-oxo-4-piperidineacetic acid ethyl ester | 
                                        57130-37-7 | 
                                        C28H37NO6 | 
                                        483.605 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (4S,5R)-(-)-1-(2-(2-Benzyloxy-3,4-dimethoxyphenyl)-ethyl)-5-ethyl-2-oxo-4-piperidineacetic Acid | 
                                        57103-66-9 | 
                                        C26H33NO6 | 
                                        455.551 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (4R,5R)-(+)-1-(2-benzyloxy-3,4-dimethoxyphenethyl)-5-ethyl-2-oxo-4-piperidineacetic acid | 
                                        57103-67-0 | 
                                        C26H33NO6 | 
                                        455.551 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (4S,5R)-1-<2-(2-(Benzyloxy)-3,4-dimethoxyphenyl)-2-hydroxyethyl>-5-ethyl-2-oxo-4-piperidineacetic Acid Ethyl Ester | 
                                        57103-64-7 | 
                                        C28H37NO7 | 
                                        499.604 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (4S,5R)-(-)-1-(2-(2-Hydroxy-3,4-dimethoxyphenyl)-ethyl)-5-ethyl-2-oxo-4-piperidineacetic Acid Ethyl Ester | 
                                        57130-36-6 | 
                                        C21H31NO6 | 
                                        393.48 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (4S,5R)-(-)-1-(2-(2-Hydroxy-3,4-dimethoxyphenyl)-ethyl)-5-ethyl-2-oxo-4-piperidineacetic Acid | 
                                        65929-06-8 | 
                                        C19H27NO6 | 
                                        365.426 |