The synthesis of 7-hydroxy-3, 9-diazabicyclo[3.3.1]nonane

7-Hydroxy-3, 9-diazabicyclo3.3.1]nonane is synthesized, starting from the dimethyl ester of the 4-hydroxypiperidine-2, 6-dicarboxylic acid, by preparing the N-benzyl derivative and cyclizing the latter with benzylamine to the benzylimide of the 1-benzyl-4-hydroxypiperidine-2, 6-dicarboxylic acid. On reduction of the given imide with lithium aluminum hydride and catalytic hydrogenolysis of the benzyl groups, the final 7-hydroxy-3,9-diazabicyclo3.3.1]nonane is obtained, the three-dimensional structure of which (chair-chair type) is proved by comparison of its methyl derivative with a known compound of demonstrated three-dimensional structure.