Exploration of synthetic routes to achieve designed vitamin B 6 models on the structural basis of functionalized dithia (2, 5) pyridinophanes from pyridoxine hydrochloride was undertaken and the catalyst potency for a racemization reaction was examined in comparison with that of pyridoxal. By the reaction of 3, 4′-O-isopropylidenepyridoxine 2′, 5′-dichloride with α, ω-dithiols, dithia (2, 5) pyridinophanes were synthesized in good ...