Nickel-catalyzed coupling reaction of cis bromide 6 and the borates 5a and 5b, prepared from the boronate esters 4a and 4b, proceeded stereospecifically to furnish 7a and 7b, which upon treatment with Bu 4 NF in THF afforded 10,11-dihydro-leukotriene B 4 (1) and the B 3 (2), respectively. In a similar way, EE ether 19 and rac-4a gave 20 and the subsequent functional group transformation afforded 10,11-dihydro-12-oxo-LTB 4 (3).