L-苯丙氨酸甲酯   、                                                                                      
(5S,8S,8aR)-8-Isopropyl-1,3-dioxo-5-phenyl-tetrahydro-oxazolo[3,4-a]pyrazine-7-carboxylic acid tert-butyl ester                                                                                                                                                                                              以
                                                                                         
二氯甲烷                                                                                  为溶剂,
                                                                                                                                                    反应 20.0h,
                                                                                                                以70%的产率得到(2S,3R,5S)-2-Isopropyl-3-((S)-1-methoxycarbonyl-2-phenyl-ethylcarbamoyl)-5-phenyl-piperazine-1-carboxylic acid tert-butyl ester