(R)-methyl 2'-(1-(tert-butoxycarbonylamino)-2-(tert-butylthio)ethyl)-5,5'-dimethyl-2,4'-bioxazole-4-carbonitrile 、
ethyl 2-diazo-3-oxo-propanoate 在
dirhodium(II) tetrakis(perfluorobutyramide) 作用下,
以
氯仿 为溶剂,
以65%的产率得到ethyl 2-[2-[2-[(1R)-2-tert-butylsulfanyl-1-[(2-methylpropan-2-yl)oxycarbonylamino]ethyl]-5-methyl-1,3-oxazol-4-yl]-5-methyl-1,3-oxazol-4-yl]-1,3-oxazole-4-carboxylate