3-Azaspiro[5.5]undecane-3-carboxylic acid, 9-oxo-, 1,1-dimethylethyl ester
1,1-Dimethylethyl 9-oxo-3-azaspiro[5.5]undecane-3-carboxylate
tert-Butyl 9-oxo-3-azaspiro[5.5]undecan-3-carboxylate
9-Oxo-3-azaspiro[5.5]undecane-3-carboxylic acid tert-butyl ester