Spiro[1H-indene-1,4′-piperidine]-3-acetic acid, 1′-[(1,1-dimethylethoxy)carbonyl]-2,3-dihydro-
1′-[(1,1-Dimethylethoxy)carbonyl]-2,3-dihydrospiro[1H-indene-1,4′-piperidine]-3-acetic acid
2-[1′-[(2-Methylpropan-2-yl)oxycarbonyl]spiro[1,2-dihydroindene-3,4′-piperidine]-1-yl]acetic acid
2-[1′-[(tert-Butoxy)carbonyl]-2,3-dihydrospiro[indene-1,4′-piperidine]-3-yl]acetic acid