Synthesis of the 7-cis isomer of the natural leukotriene d4

Methyl 5(S), 6(S)-oxido-11-oxo-7-cis-9-trans-undecadienoate 5 was prepared and used for the synthesis of the novel 7-cis-LTD4 (9) as well as, after isomerization to the all-trans dienal ester 3, for that of the natural leukotrienes.