1,1-dimethylethyl 1-oxo-2-oxa-8-azaspiro[4,5]decane-8-carboxylate
2-Benzyl-1-oxo-2,7-diaza-spiro[3.5]nonane-7-carboxylic acid tert-butyl ester
tert-butyl 4-(hydroxymethyl)piperidin-1-carboxylate
4-(iodomethyl)piperidine-1,4-dicarboxylic acid 1-tert-butyl ester 4-ethyl ester
4-(4-but-2-ynyloxy-phenylsulfanyl)-piperidine-1,4-dicarboxylic acid mono-tert-butyl ester