New Approach to<i>N</i>-substituted-1,2,3,6-tetrahydro-pyridine-4-carbaldehyde, a Precursor for Synthesizing Aricept<sup>®</sup>, Isoguvacine, and Deethylibophyllidine
A new route towards the synthesis of N-substituted-4-formylpiperidine using N-benzyl or tryptaminylsulfonylacetamide and-unsaturated ester as starting materials is described. Formal synthesis of Aricept ® , deethylibophyllidine, and isoguvacine, which have potential biological activities, were synthesized via this strategy.