(R)-tert-butyl (2-(1'-benzyl-1-(2-fluoro-6-(trifluoromethyl)benzyl)-2,4-dioxo-1H-spiro[furo[3,4-d]pyrimidine-5,4'-piperidin]-3(2H,4H,7H)-yl)-1-phenylethyl)carbamate 、
1'-benzyl-1-(2-fluoro-6-(trifluoromethyl)benzyl)-6,7-dihydrospiro[cyclopenta[d]pyrimidine-5 ,4'-piperidine]-2,4( 1H,3H)-dione 以to obtain the title compound as white solid (14 mg, yield: 48%)的产率得到(R)-tert-butyl (2-(1'-benzyl-1-(2-fluoro-6-( trifluoromethyl)benzyl)-2,4-dioxo-1 ,2,6,7-tetrahydrospiro[cyclopenta[d]pyrimidine-5,4'-piperidin]-3(4H)-yl)-1-phenylethyl)carbamate