Abstract
13L‐Hydroperoxy‐9,11‐octadecadienoic acid was decomposed rapidly in the presence of hemoglobin. The product consisted of five major compounds, i.e. 13‐keto‐9,11‐octadecadienoic acid, 13L‐hydroxy‐9,11‐octadecadienoic acid,erythro‐11‐hydroxy‐12,13‐epoxy‐9‐octadecenoic acid,threo‐11‐hydroxy‐12,13‐epoxy‐9‐octadecenoic acid, and 9DL‐hydroxy‐12,13‐epoxy‐10‐octadecenoic acid.