51 a (i) Catecholborane, THF;(ii) Pd (PPh3),, THF, 1 N NaOH. acids with soybean lipoxygenase, followed by sodium borohydride reduction and chromatographic purification.'5-HETE (56) was similarly converted to 5, 15-diHETE (58). The 15-HETE derivatives 4-6 were prepd. by using conventional methods. 5, 15-DiHETE easily cyclized to the &lactone 59 upon heating under reflux in benzene in the presence of p- ...