for the following products
1,1-Dimethylethyl ester2,5-diazabicyclo[2.2.1]heptane-2-carboxylic acid | 2,5-Diaza-bicyclo[2.2.1]heptane-2-carboxylic acid tert-butyl ester | tert-Butyl 2,5-diazabicyclo[2.2.1]heptane-2-carboxylate and N-Boc-2,5-Diaza-bicyclo[2.2.1]heptane
