The products of the photolysis of vitamin K_1 in benzene solution were subjected to thin layer chromatograpy using silica gel and chloroform as solvent to give colored spots with Rf of 0 (spot 4), 0.21 (spot 5) and colorless spot with Rf of 0.56 (spot 6) along with other spots. Spot 5 and 6 were elucidated as 5-hydroxy-4-methyl-6,7-benzocoumaran-3-one and phytone, and spot 4 was revealed to be polymer which had the same structure as spot 5.
