methyl (S)-4-methyl-2-(2-oxo-2,5-dihydro-1H-pyrrol-1-yl)pentanoate   、                                                                                      
                                                                                                                                                                                              以
                                                                                         
二氯甲烷                                                                                  为溶剂,
                                                                                                                                                                                        生成                                                 (S)-methyl 2-(4-(4-ethyl-3,5-dimethyl-1H-pyrrol-2-yl)-2-oxopyrrolidin-1-yl)-4-methylpentanoate   、                                                                                             methyl 2-(4-(4-ethyl-3,5-dimethyl-1H-pyrrol-2-yl)-2-oxopyrrolidin-1-yl)-4-methylpentanoate