A Novel <i>C</i>₂-Symmetric 2,6-Diallylpiperidine Carboxylic Acid Methyl Ester as a Promising Chiral Building Block for Piperidine-Related Alkaloids^†

<i>C</i>₂-Symmetric 2,6-diallylpiperidine 1-carboxylic acid methyl ester (<b>5</b>) was examined via the double asymmetric allylboration of glutaraldehyde followed by aminocyclization and carbamation as a promising chiral building block for piperidine-related alkaloids, which were synthesized by the desymmetrization of <b>5</b> using intramolecular iodocarbamation as a key step.