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