2-[(5-cyclohexyl-2-cyclohexylmethyl-3-oxo-pentanoyl)-(4-methoxy-benzyl)-amino]-propionic acid                                                                                                                                                              在
                                                                                                                                                                                 2-bromo-N-propylpyridinium triflate   、                                                                                                  
4-吡咯烷基吡啶   、                                                                                                  
N,N-二异丙基乙胺                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
二氯甲烷                                                                                  为溶剂,
                                                                                                                                                    反应 4.16h,
                                                                                                                生成                                                 5-(2-cyclohexyl-ethyl)-4-cyclohexylmethyl-2-(4-methoxy-benzyl)-1-methyl-6-oxa-2-aza-bicyclo[3.2.0]heptane-3,7-dione   、                                                                                             5-(2-cyclohexyl-ethyl)-4-cyclohexylmethyl-2-(4-methoxy-benzyl)-1-methyl-6-oxa-2-aza-bicyclo[3.2.0]heptane-3,7-dione