A Facile Synthesis of Racemic 2-Aminomethyl-4-oxo-piperidine Intermediates.

Abstract Facile access to the 2-substituted piperidine nucleus was achieved by a 3-component hetero Diels-Alder reaction. The use of an appropriately functionalized imine allowed the installation of a protecting group for both the piperidine and 2-position side chain nitrogens in one step. Also, by employing 2-trimethylsiloxy-1,3-butadiene, a reduction step was avoided, thus providing rapid entry into the piperidine core structure. This protocol led to the synthesis of some racemic 2-aminomethyl-4-oxo-piperidines; intermediates that were synthesized in multigram quantities.