The kinetics and mechanism of condensation of pyridoxal hydrochloride with L-α-asparagine, L‑α- and D-α-aspartic acids are analyzed via UV spectroscopy and polarimetry. It is found that L‑α‑asparagine containing α-NH2 and γ-NH2 groups interacts with pyridoxal via the γ-NH2 group, forming Schiff bases that are resistant to chemical transformations. Rearrangement produces Schiff bases that form the cyclic structure from the amino acid moiety. L-α- and D-α-aspartic acids interacting with pyridoxal via α‑NH2 groups create Schiff bases that form quinoid structures after elimination of α-hydrogen or СО2. Their subsequent hydrolysis results in pyridoxamine, α-ketoacids, and aldehyde acids, respectively. Schemes of the condensation mechanisms of L-α-asparagine, L-α-, D-α-aspartic acids with pyridoxal hydrochloride are proposed.