(R)-ethyl 2-(4-(1-amino-2-(1-(2-fluoro-6-(trifluoromethyl)benzyl)-2,4-dioxo-1'-((5-(trifluoromethyl)furan-2-yl)methyl)-1H-spiro[furo[3,4-d]pyrimidine-5,4'-piperidin]-3(2H,4H,7H)-yl)ethyl)phenoxy)acetate

(R)-ethyl 2-(4-(1-((tert-butoxycarbonyl)amino)-2- hydroxyethyl)phenoxy) acetate

(R)-2-((tert-butoxycarbonyl)amino)-2-(4-(2-ethylacetoxy)phenyl)ethyl methanesulfonate

(R)-ethyl 2-(4-(1-((tert-butoxycarbonyl)amino)-2-(1-(2- fluoro-6-(trifluoromethyl)benzyl)-2,4-dioxo-1'-((5-(trifluoromethyl)furan-2-yl)methyl)-1H-spiro[furo[3,4-d]pyrimidine-5,4'-piperidin]-3(2H,4H,7H)-yl)ethyl)phenoxy)acetate