for the following products
2,3-Dihydro-3-oxo-spiro[1H-indene-1,4'-piperidine]-1'-carboxylic acid tert-butyl ester | Spiro[1H-indene-1,4'-piperidine]-1'-carboxylic acid, 2,3-dihydro-3-oxo-, 1,1-dimethylethyl ester | tert-Butyl 3-oxo-2,3-dihydrospiro[indene-1,4'-piperidine]-1'-carboxylate and N-Boc-1-[4-Spiro-piperidine]-3-indanone
