Abstract5‐Hydroxy‐7‐methoxy‐2,2‐dimethyl‐6‐octyl(and 8‐octyl)‐4‐chromanones (2aand2b) were synthesized via 5,7 dihydroxy‐2,2‐dimethyl‐6‐octyl (and 8‐octyl)‐4‐chromanones (1aand1b) from phloroglucinol as a starting material. Cyclohexane solutions of1a, 1b, 2a, and2bwere irradiated. The photostability of2aand2bwas found to be better than that of1aand1b. Poly(vinyl chloride) film containing 6, 7 wt.‐% of2bwas found to be