Schiff Bases from TRIS and Formylpyridines: Structure and Mechanistic Rationale Aided by DFT Calculations

This paper describes the synthesis and structural elucidation of 1,3‐oxazolidines derived from tris(hydroxymethyl)aminomethane (TRIS) and pyridine‐based aldehydes. Divergent results were obtained with other formylpyridines, such aspyridoxal, in which intramolecular hydrogen‐bonding largely stabilizes the iminic structure. The oxazolidines may undergo ring‐opening under acetylating conditions to afford imines through different mechanistic pathways, which have also been evaluated by DFT calculations.