Studies on the Syntheses of Vitamin B₆ Derivatives

Catalytic Reduction of Hydroxymethyl Group Substituted in the Pyridine Ring

Abstract

The hydroxymethyl groups in pyridoxine, pyridoxamine, pyridoxal, and their derivatives form deoxygenated derivatives of pyridoxine by catalytic reduction over palladium-carbon. Similarly, 2-, 3-, and 4-pyridinemethanols also form corresponding picolines by catalytic reduction. The presence of water is necessary as a solvent in the case of pyridoxine derivatives while the solvent is not required in that of pyridinemethanols. Since the acylation of the hydroxymethyl group in both derivatives results in more facile reduction to methyl group, this reaction was considered to be the direct hydrogenolysis.