tert-Butyl 3-[N-(tert-butoxy-carbonyl)methyl-amino]-4-methoxy-imino-3-methyl-piperidine-1-carboxyl-ate.

The title compound, C(18)H(33)N(3)O(5), was prepared from N-tert-butoxy-carbonyl-4-piperidone using a nine-step reaction, including condensation, methyl-ation, oximation, hydrolysis, esterification, ammonolysis, Hoffmann degradation, tert-butoxy-carbonyl protection and methyl-ation. The E configuration of the methyl-oxime geometry of the compound is confirmed.