Suggested Reaction 1.3.3.-

Left

(9Z,12Z)-(7S,8S)-Dihydroxyoctadeca-9,12-dienoate
+O2

Right

(9Z,12Z,15Z)-(7S,8S)-Dihydroxyoctadeca-9,12,15-trienoate
+H2O2

[BiSSCat | GREP ]