(3S)-3-氨基-N-环丙基-2-羟基己酰胺 、
(5R,8S)-7-((S)-2-(2-cyclohexylacetamido)-3,3-dimethylbutanoyl)-2-oxo-3-phenyl-1-oxa-3,7-diazaspiro[4.4]nonane-8-carboxylic acid 以gave 20 mg (30 μmol) of (5R,8S)-7-((S)-2-(2-cyclohexylacetamido)-3,3-dimethylbutanoyl)-N-((3S)-1-(cyclopropylamino)-2-hydroxy-1-oxohexan-3-yl)-2-oxo-3-phenyl-1-oxa-3,7-diazaspiro[4.4]nonane-8-carboxamide (G2)的产率得到(5R,8S)-7-((S)-2-(2-cyclohexylacetamido)-3,3-dimethylbutanoyl)-N-((3S)-1-(cyclopropylamino)-2-hydroxy-1-oxohexan-3-yl)-2-oxo-3-phenyl-1-oxa-3,7-diazaspiro[4.4]nonane-8-carboxamide