Abstract
One of the main compounds formed from 13L‐hydroperoxy‐9cis,11trans‐octadecadienoic acid anaerobically at 100 C in aqueous ethanol was found to bethreo‐11‐hydroxy‐12,13‐epoxy‐9‐octadecenoic acid. The major part (ca. 90%) of this compound was formed from the fatty acid hydroperoxide in a reaction involvingcis‐addition to the Δ11 double bond of the proximally linked hydroperoxide oxygen and hydroxyl ion or hydroxyl radical from the solvent. A small part (ca. 10%) was formed bycis‐addition of the two hydroperoxide oxygens to the Δ11 double bond. 11‐Hydroxy‐12,13‐epoxy‐9‐octadecenoic acid and its isomer, tentatively identified as 11‐hydroxy‐9,10‐epoxy‐12‐octadecenoic acid, also were isolated from a sample of autoxidized linoleic acid.